Negation

A finite indicative verb (or its clause) is negated by placing the word not after an auxiliary, modal or other "special" verb such as do, can or be. For example, the clause I go is negated with the appearance of the auxiliary do, as I do not go. When the affirmative already uses auxiliary verbs (I am going), no other auxiliary verbs are added to negate the clause (I am not going). (Until the period of early Modern English, negation was effected without additional auxiliary verbs: I go not.)

Most combinations of auxiliary verbs etc. with not have contracted forms: don't, can't, isn't, etc. (Also the uncontracted negated form of can is written as a single word cannot.) On inversion of subject and verb (such as in questions), the subject may be placed after a contracted negated form: Should he not pay? or Shouldn't he pay?

Other elements, such as noun phrases, adjectives, adverbs, infinitive and participial phrases, etc., can be negated by placing the word not before them: not the right answer, not interesting, not to enter, not noticing the train, etc.

When other negating words such as never, nobody, etc. appear in a sentence, the negating not is omitted (unlike its equivalents in many languages): I saw nothing or I didn't see anything, but not (except in non-standard speech) I didn't see nothing. Such negating words generally have corresponding negative polarity items (ever for never, anybody for nobody, etc.) which can appear in a negative context, but are not negative themselves (and can thus be used after a negation without giving rise to double negatives).

Adjective and Adverb

English distinguishes between adjectives, which qualify nouns and pronouns, and adverbs, which mainly modify verbs, adjectives, or other adverbs. Not all languages make this exact distinction; many (including English) have words that can function as either. For example, in English, fast is an adjective in "a fast car" (where it qualifies the noun car) but an adverb in "he drove fast" (where it modifies the verb drove).

Adjective

An adjective is word whose main syntactic role is to modify a noun or noun phrase. Its semantic role is to change information given by the noun.

Adjectives are one of the main parts of speech of the English language, although historically they were classed together with nouns. Certain words that were traditionally considered to be adjectives, including the, this, my, etc., are today usually classed separately, as determiners.

Adverb

An adverb is a word that modifies a verb, adjective, determiner, clause, preposition, or sentence. Adverbs typically express manner, place, time, frequency, degree, level of certainty, etc., answering questions such as how?, in what way?, when?, where?, and to what extent?. This function is called the adverbial function, and may be realized by single words (adverbs) or by multi-word expressions (adverbial phrases and adverbial clauses).

Adverbs are traditionally regarded as one of the parts of speech. However, modern linguists note that the term "adverb" has come to be used as a kind of "catch-all" category, used to classify words with various different types of syntactic behavior, not necessarily having much in common except that they do not fit into any of the other available categories (noun, adjective, preposition, etc.)

Active and Passive Voice

The active voice (where the verb's subject is understood to denote the doer, or agent), of the denoted action) is the unmarked voice in English.

To form the passive voice (where the subject denotes the undergoer, or patient), of the action), a periphrastic construction is used.

In the canonical form of the passive, a form of the auxiliary verb be (or sometimes get) is used, together with the past participle of the lexical verb. Passive voice can be expressed in combination together with tenses, aspects and moods, by means of appropriate marking of the auxiliary (which for this purpose is not a stative verb, i.e. it has progressive forms available).

For example:

• This room is tidied regularly. (simple present passive)
• It had already been accepted. (past perfect passive)

• Dinner is being cooked right now. (present progressive passive)

The passive forms of certain of the combinations involving the progressive aspect are quite rare; these include the present perfect progressive (it has been being written), past perfect progressive (it had been being written), future progressive (it will be being written), future perfect progressive (it will have been being written), conditional progressive (it would be being written) and conditional perfect progressive (it would have been being written). Because of the awkwardness of these constructions, they may be paraphrased, for example using the expression in the process of (it has been in the process of being written, it will be in the process of being written, and similar).

The uses of these various passive forms are analogous to those of the corresponding tense–aspect–mood combinations in the active voice.

Adverb

An adverb is a word that modifies a verb, adjective, determiner, clause, preposition, or sentence. Adverbs typically express manner, place, time, frequency, degree, level of certainty, etc., answering questions such as how?, in what way?, when?, where?, and to what extent?. This function is called the adverbial function, and may be realized by single words (adverbs) or by multi-word expressions (adverbial phrases and adverbial clauses).

Adverbs are traditionally regarded as one of the parts of speech. However, modern linguists note that the term "adverb" has come to be used as a kind of "catch-all" category, used to classify words with various different types of syntactic behavior, not necessarily having much in common except that they do not fit into any of the other available categories (noun, adjective, preposition, etc.)

Adjective

In linguistics, an adjective is a describing word, the main syntactic role of which is to qualify a noun or noun phrase, giving more information about the object signified.

Adjectives are one of the English parts of speech, although they were historically classed together with the nouns. Certain words that were traditionally considered to be adjectives, including the, this, my, etc., are today usually classed separately, as determiners.

Conditional Sentence

As is typical for many languages, full conditional sentences in English consist of a condition clause or protasis specifying a condition or hypothesis, and a consequence clause or apodosis specifying what follows from that condition. The condition clause is a dependent clause, most commonly headed by the conjunction if, while the consequence is contained in the main clause of the sentence. Either clause may appear first.

Different types of conditional sentences (depending largely on whether they refer to a past, present or future time frame) require the use of particular verb forms (tenses and moods) to express the condition and the consequence. In English language teaching the most common patterns are referred to as first conditional, second conditional and third conditional; there is also a zero conditional and mixed conditional.

Clause

In language, a clause is the smallest grammatical unit that can express a complete proposition. A typical clause consists of a subject and a predicate, the latter typically a verb phrase, a verb with any objects and other modifiers. However, the subject is sometimes not said or explicit, often the case in null-subject languages if the subject is retrievable from context, but it sometimes also occurs in other languages such as English (as in imperative sentences and non-finite clauses).

A simple sentence usually consists of a single finite clause with a finite verb that is independent. More complex sentences may contain multiple clauses. Main clauses (matrix clauses, independent clauses) are those that can stand alone as a sentence. Subordinate clauses (embedded clauses, dependent clauses) are those that would be awkward or incomplete if they were alone.

Simple Past

The simple past, past simple or past indefinite, sometimes called the preterite, is the basic form of the past tense in Modern English. It is used principally to describe events in the past, although it also has some other uses. Regular English verbs form the simple past in -ed; however there are a few hundred irregular verbs with different forms.

The term "simple" is used to distinguish the syntactical construction whose basic form uses the plain past tense alone, from other past tense constructions which use auxiliaries in combination with participles, such as the past perfect and past progressive.

Formation

Regular verbs form the simple past end-ed; however there are a few hundred irregular verbs with different forms. For details see.

Most verbs have a single form of the simple past, independent of the person or number of the subject (there is no addition of -s for the third person singular as in the simple present).

However, the copula verb be has two past tense forms: was for the first and third persons singular, and were in other instances.

The form were can also be used in place of was in conditional clauses and the like; for information on this, see subjunctive.

This is the only case in modern English where a distinction in form is made between the indicative and subjunctive moods in the past tense.

Questions, other clauses requiring inversion, negations with not, and emphatic forms of the simple past use the auxiliary did.

A full list of forms is given below, using the (regular) verb help as an example:

• Basic simple past:
  • I/you/he/she/it/we/they helped
• Expanded (emphatic) simple past:
  • I/you/he/she/it/we/they did help
• Question form:
  • Did I/you/he/she/it/we/they help?
• Negative:
  • I/you/he/she/it/we/they did not (didn't) help
• Negative question:
  • Did I/you/he/she/it/we/they not help? / Didn't I/you/he/she/it/we/they help?

Usage

The simple past is used for a single event (or sequence of such events) in the past, and also for past habitual action:

• He took the money and ran.
• I visited them every day for a year.

It can also refer to a past state:

• I knew how to fight even as a child.

For action that was ongoing at the time referred to, the past progressive is generally used instead (e.g. I was cooking). The same can apply to states, if temporary (e.g. the ball was lying on the sidewalk), but some stative verbs do not generally use the progressive aspect at all, and in these cases the simple past is used even for a temporary state:

• The dog was in its kennel.

However, with verbs of sensing, it is common in such circumstances to use could see in place of saw, could hear in place of heard, etc.

• I felt cold.

If one action interrupts another, then it is usual for the interrupted (ongoing) action to be expressed with the past progressive, and the action that interrupted it to be in the simple past:

• Your mother called while you were cooking.

The simple past is often close in meaning to the present perfect.

The simple past is used when the event happened at a particular time in the past, or during a period which ended in the past (i.e. a period that does not last up until the present time).

This time frame may be explicitly stated, or implicit in the context (for example the past tense is often used when describing a sequence of past events).

• I was born in 1980.
• We turned the oven off two minutes ago.
• I came home at 6 o'clock.
• When did they get married?
• We wrote two letters this morning.
• She placed the letter on the table, sighed, and left the house.Contrast these examples with those given at.

Note also that for past actions that occurred before the relevant past time frame, the past perfect is used.

Various compound constructions exist for denoting past habitual action.

The sentence When I was young, I played football every Saturday might alternatively be phrased using used to (... I used to play ...) or using would (... I would play...).

The simple past also has some uses in which it does not refer to a past time.

• If he walked faster, he would get home earlier.
• I wish I knew what his name was.

These are generally in condition clauses and some other dependent clauses referring to hypothetical circumstances, as well as certain expressions of wish:

• He said he wanted to go on the slide.

Past Progressive

The past progressive or past continuous construction combines progressive aspect with past tense, and is formed using the past tense of be (was or were) with the present participle of the main verb.

It indicates an action that was ongoing at the past time being considered:

• At three o'clock yesterday, I was working in the garden. For stative verbs that do not use the progressive aspect, the simple past is used instead (At three o'clock yesterday we were in the garden).

The past progressive is often used to denote an action that was interrupted by an event, or for two actions taking place in parallel:

• While I was washing the dishes, I heard a loud noise.
• While you were washing the dishes, Sue was walking the dog.(Interrupted actions in the past can also sometimes be denoted using the past perfect progressive.)

The past progressive can also be used to refer to past action that occurred over a range of time and is viewed as an ongoing situation:

• I was working in the garden all day yesterday. That could also be expressed using the simple past, as I worked..., which implies that the action is viewed as a unitary event (although the effective meaning is not very different).

Past Perfect

The past perfect, sometimes called the pluperfect, combines past tense with perfect aspect; it is formed by combining had (the past tense of the auxiliary have) with the past participle of the main verb.

It is used when referring to an event that took place prior to the time frame being considered.

This time frame may be stated explicitly, as a stated time or the time of another past action:

• We had finished the job by 2 o'clock.
• He had already left when we arrived.

The time frame may also be understood implicitly from the previous or later context:

• I was eating ... I had invited Jim to the meal but he was unable to attend. (i.e. I invited him before I started eating)
• I had lost my way. (i.e. this happened prior to the time of the past events I am describing or am about to describe)

Compare He had left when we arrived (where his leaving preceded our arrival), with the form with the simple past, He left when we arrived (where his leaving was concurrent with or shortly after our arrival).

Note that unlike the present perfect, the past perfect can readily be used with an adverb specifying a past time frame for the occurrence.

For example, while it is incorrect to say I have done it last Friday (the use of last Friday, specifying the past time, would require the simple past rather than the present perfect), there is no such objection to a sentence like "I had done it the previous Friday".

The past perfect can also be used for states or repeated occurrences pertaining over a period up to a time in the past, particularly in stating "for how long" or since when". However, if the state is temporary and the verb can be used in the progressive aspect, the past perfect progressive would normally be used instead. Some examples with the plain past perfect:

• I had lived in that house for 10 years.
• The children had been in their room since lunchtime.

Past Perfect Progressive

The past perfect progressive or past perfect continuous (also known as the pluperfect progressive or pluperfect continuous) combines perfect progressive aspect with past tense.

It is formed by combining had (the past tense of auxiliary have), been (the past participle of be), and the present participle of the main verb.

Uses of the past perfect progressive are analogous to those of the present perfect progressive, except that the point of reference is in the past.

For example:

• I was tired because I had been running.
• By yesterday morning they had already been working for twelve hours.
• Among the witnesses was John Smith, who had been staying at the hotel since July 10.

This form is sometimes used for actions in the past that were interrupted by some event (compare the use of the past progressive as given above).

For example:

• I had been working on my novel when she entered the room to talk to me.

This implies that I stopped working when she came in (or had already stopped a short time before); the plain past progressive (I was working...) would not necessarily carry this implication.

If the verb in question does not use the progressive aspect, then the plain past perfect is used instead.

The past perfect progressive may also have additional specific uses similar to those of the plain past perfect.

Simple Future

The term simple future, future simple or future indefinite, as applied to English, generally refers to the combination of the modal auxiliary verb will with the bare infinitive of the main verb.

Sometimes (particularly in more formal or old-fashioned English) shall is preferred to will when the subject is first person (I or we).

The auxiliary is often contracted to 'll.

This construction can be used to indicate what the speaker views as facts about the future, including confident predictions:

• The sun will rise tomorrow at 6:14.
• It will rain later this week.

It may be used to describe future circumstances that are subject to some condition:

• He will go there if he can.

However English also has other ways of referring to future circumstances. For planned or scheduled actions the present progressive or simple present may be used. There is also a going-to future, common in colloquial English, which is often used to express intentions or predictions (I am going to write a book some day; I think that it is going to rain). Use of the will/shall construction when expressing intention often indicates a spontaneous decision:

• I know! I'll use this book as a door stop.

Compare I'm going to use..., which implies that the intention to do so has existed for some time.

Use of present tense rather than future constructions in condition clauses and certain other dependent clauses is described below under and. The modal verbs will and shall also have other uses besides indicating future time reference. For example:

• I will pass this exam. (often expresses determination in addition to futurity)
• You will obey me! (insistence)
• I will not do it! (negative insistence, refusal)
• At this moment I will tolerate no dissent. (strong volition)
• He hasn't eaten all day; he will be hungry now. (confident speculation about the present)
• One of his faults is that he will make trouble unnecessarily. (habit)
• Shall we get to work? (suggestion)

Future Progressive

The future progressive or future continuous combines progressive aspect with future time reference; it is formed with the auxiliary will (or shall in the first person, the bare infinitive be, and the present participle of the main verb.

It is used mainly to indicate that an event will be in progress at a particular point in the future:

• This time tomorrow I will be taking my driving test.
• I imagine we will already be eating when you arrive.

The usual restrictions apply, on the use both of the future and of the progressive: simple rather than progressive aspect is used with some stative verbs, and present rather than future constructions are used in many dependent clauses. The same construction may occur when will or shall is given one of its other uses, for example:

• He will be sitting in his study at this time. (confident speculation about the present)

Future Perfect

The future perfect combines aspect with future time reference.

It consists of the auxiliary will (or sometimes shall in the first person, as above), the bare infinitive have, and the past participle of the main verb.

It indicates an action that is to be completed sometime prior to a future time of perspective, or an ongoing action continuing up to a future time of perspective (compare uses of the present perfect above).

• I shall have finished my essay by Thursday.
• When I finally search him he will have disposed of the evidence.
• By next year we will have lived in this house for half a century.

For the use of the present tense rather than future constructions in certain dependent clauses.

The same construction may occur when will or shall is given one of its other meanings; for example:

• He will have had his tea by now. (confident speculation about the present)
• You will have completed this task by the time I return, is that understood? (giving instruction)

Future Perfect Progressive

The future perfect progressive or future perfect continuous combines perfect progressive aspect with future time reference.

It is formed by combining the auxiliary will (or sometimes shall, as above), the bare infinitive have, the past participle been, and the present participle of the main verb.

Uses of the future perfect progressive are analogous to those of the present perfect progressive, except that the point of reference is in the future. For example:

• He will be very tired because he will have been working all morning.
• By 6 o'clock we will have been drinking for ten hours.

For the use of present tense in place of future constructions in certain dependent clauses.

The same construction may occur when the auxiliary (usually will) has one of its other meanings, particularly expressing a confident assumption about the present:

• No chance of finding him sober now; he'll have been drinking all day.

Simple

"Simple" forms of verbs are those appearing in constructions not marked for either progressive or perfect aspect (I go, I don't go, I went, I will go, etc., but not I'm going or I have gone).

Simple constructions normally denote a single action (perfective aspect), as in Brutus killed Caesar, a repeated action (habitual aspect), as in I go to school, or a relatively permanent state, as in We live in Dallas. They may also denote a temporary state (imperfective aspect), in the case of stative verbs that do not use progressive forms.

Progressive

The progressive or continuous aspect is used to denote a temporary action or state that began at a previous time and continues into the present time (or other time of reference). It is expressed using a form of the auxiliary verb to be (conjugated appropriately for tense etc.) together with the present participle (-ing form) of the main verb: I am reading; Were you shouting?; He will be sitting over there.

Certain stative verbs make limited use of progressive aspect. Their nonprogressive forms (simple or nonprogressive perfect constructions) are used in many situations even when expressing a temporary state.

The main types are described below.

• The copular verb to be does not normally use progressive forms (I am happy, not I am being happy). However its progressive aspect is used in appropriate situations when the verb expresses the passive voice (We are being followed), and when it has the meaning of "behave" or "act as" (You are being very naughty; He's being a pest).
• The verb to have does not use progressive forms when it expresses possession), broadly understood (I have a brother, not I'm having a brother), but it does use them in its active meanings (I'm having a party; She's having a baby; He was having a problem starting his car). Other verbs expressing a state of possession or similar, such as possess, own, belong and owe, also do not normally use progressive forms.
• Verbs of mental state, sense perception and similar (know, believe, want, think, see, hear, need, etc.) are generally used without progressive aspect, although some of them can be used in the progressive to imply an ongoing, often temporary situation (I am feeling lonely), or an activity (I am thinking about a problem).
• Verbs denoting positional state normally do use the progressive if the state is temporary: He is standing in the corner. (Compare permanent state: London stands on the banks of the Thames.)

Perfect Progressive

The perfect and progressive (continuous) aspects can be combined, usually in referring to the completed portion of a continuing action or temporary state: I have been working for eight hours. Here a form of the verb have (denoting the perfect) is used together with been (the past participle of be, denoting the progressive) and the present participle of the main verb.

In the case of the stative verbs, which do not use progressive aspect, the plain perfect form is normally used in place of the perfect progressive: I've been here for half an hour (not I've been being here...).

Perfect

The perfect aspect is used to denote the circumstance of an action's being complete at a certain time. It is expressed using a form of the auxiliary verb have (appropriately conjugated for tense etc.) together with the past participle of the main verb: She has eaten it; We had left; When will you have finished?

Perfect forms can also be used to refer to states or habitual actions, even if not complete, if the focus is on the time period before the point of reference (We had lived there for five years). If such a circumstance is temporary, the perfect is often combined with progressive aspect.

The implications of the present perfect (that something occurred prior to the present moment) are similar to those of the simple past, although the two forms are generally not used interchangeably – the simple past is used when the time frame of reference is in the past, while the present perfect is used when it extends to the present.

For all uses of specific perfect constructions, see the sections on the present perfect, past perfect, future perfect and conditional perfect.

By using nonfinite forms of the auxiliary have, perfect aspect can also be marked on infinitives (as in should have left and expect to have finished working), and on participles and gerunds (as in having seen the doctor).

Note that while all of the constructions referred to here are commonly referred to as perfect (based on their grammatical form), some of them, particularly nonpresent and nonfinite instances, might not be considered truly expressive of the perfect aspect. This applies particularly when the perfect infinitive is used together with modal verbs: for example, he could not have been a genius might be considered (based on its meaning) to be a past tense of he cannot/could not be a genius; such forms are considered true perfect forms by some linguists but not others.

Perfect Progressive

The perfect and progressive (continuous) aspects can be combined, usually in referring to the completed portion of a continuing action or temporary state: I have been working for eight hours. Here a form of the verb have (denoting the perfect) is used together with been (the past participle of be, denoting the progressive) and the present participle of the main verb.

In the case of the stative verbs, which do not use progressive aspect, the plain perfect form is normally used in place of the perfect progressive: I've been here for half an hour (not I've been being here...).

Subjunctive Mood

The subjunctive mood in English is used to form sentences that do not describe known objective facts, but rather wishes or hypothetical suppositions. These include statements about one's state of mind, such as opinion, belief, purpose, intention, or desire. The subjunctive mood, such as She suggests that he speak English, contrasts with the indicative mood, which is used for statements of fact, such as He speaks English.

In Modern English, the subjunctive form of a verb often looks identical to the indicative form, and thus subjunctives are not a very visible grammatical feature of English. For most verbs, the only distinct subjunctive form is found in the third person singular of the present tense, where the subjunctive lacks the -s ending: It is necessary that he see a doctor (contrasted with the indicative he sees). The verb be, however, has not only a distinct present subjunctive (be, as in I suggest that he be removed) but also a past subjunctive were (as in If he were rich, ...).

These two tenses of the subjunctive have no particular connection in meaning with present and past time. Terminology varies; sometimes what is called the present subjunctive here is referred to simply as the subjunctive, and the form were may be treated just as an alternative irrealis form of was rather than a past subjunctive.

Another case where present-subjunctive forms are distinguished from indicatives is when they are negated: compare I recommend that they not enter the competition (subjunctive) with I hope that they do not enter the competition (indicative).

Past Subjunctive Mood

The only distinct past subjunctive form in English (i.e., form that differs from the corresponding past indicative) is were, which differs when used with a first or third person singular subject (where the indicative form is was). As with the present subjunctive, the name past subjunctive refers to the form of the verb rather than its meaning; it need not (and in fact usually does not) refer to past time. The main use of the past subjunctive form, were, which is also known as the irrealis is in counterfactual if clauses:

• If I were your wife, I would put poison in your coffee. [Attributed to Lady Astor, speaking to Winston Churchill]

The simple (indicative) past form was is very common in sentences of this type, though the Random House College Dictionary states "Although the [were] subjunctive seems to be disappearing from the speech of many, its proper use is still a mark of the educated speaker." When were is used, an inverted form without if is possible; this is not possible with was.

A common expression involving were is if I were you. The same principles of usage apply to the compound past subjunctive form were to..., which appears in second conditional condition clauses, usually with hypothetical future reference:

• If she were to go... or Were she to go... (equivalent to if she went)

The past subjunctive form may be used similarly to express counterfactual conditions after suppose, as if, as though, unless, imagine etc.

• Suppose that I were there now.
• She looks as though she were going to kill him.
• Try to imagine he were here.
• Try to imagine a tool that made that easy for citizens.

There is also the set expression as it were.

The past subjunctive can also be used in some that clauses expressing a wish contrary to fact or unlikely to be fulfilled:

• I wish [that] he were here now.
• If only the door were unlocked.
• I would rather [that] she were released.
• Would that it were true!
• Oh that it were so.

However, the use of the subjunctive with words such as wish is seldom obligatory. The example with would rather can be cast in the present subjunctive, expressing greater confidence that the action is feasible:

• I would rather she be released.

Modal Verb

English has the modal verbs can, could, may, might, must, shall, should, will, would, and also (depending on classification adopted) ought (to), dare, need, had (better), used (to). These do not add -s for the third-person singular, and they do not form infinitives or participles; the only inflection they undergo is that to a certain extent could, might, should and would function as preterites (past tenses) of can, may, shall and will respectively.

A modal verb can serve as the finite verb introducing a verb catena, as in "he might have been injured then". These generally express some form of modality (possibility, obligation, etc.), although will and would (and sometimes shall and should) can serve – among their other uses – to express future time reference and conditional mood.

Relative Clause

A relative clause is a kind of subordinate clause that contains the element whose interpretation is provided by an antecedent on which the subordinate clause is grammatically dependent; that is, there is an anaphoric relation between the relativized element in the relative clause and antecedent on which it depends.

Typically, a relative clause modifies a noun or noun phrase, and uses some grammatical device to indicate that one of the arguments within the relative clause has the same referent as that noun or noun phrase. For example, in the sentence *I met a man who wasn't there*, the subordinate clause who wasn't there is a relative clause, since it modifies the noun man, and uses the pronoun who to indicate that the same "man" is referred to within the subordinate clause (in this case, as its subject).

In many European languages, relative clauses are introduced by a special class of pronouns called relative pronouns, such as who in the example just given.

Restrictive and Non-restrictive

Bound relative clauses may or may not be restrictive. Whereas a non-restrictive or non-defining relative clause merely provides supplementary information, a restrictive or defining relative clause modifies the meaning of its head word (restricts its possible referent).

For example:

• *The man who lives in this house has not been seen for days. This (who lives in this house*) is a restrictive relative clause, modifying the meaning of man, and essential to the sentence (if the clause were omitted, it would no longer be known which man is being referred to). If the bold part is deleted the remaining part does not provide the sense.
• The mayor, who lives in this house, has not been seen for days. This is a non-restrictive relative clause, since it provides supplementary information about the mayor, but is not essential to the sentence – if the clause were omitted, it would still be known which mayor is meant. If the bold part is deleted the remaining part provides the sense. In speaking it is natural to make slight pauses around non-restrictive clauses, and in English this is shown in writing by commas (as in the examples).

Another difference in English is that only restrictive relative clauses may be introduced with that or use the "zero" relative pronoun. In colloquial speech, a non-restrictive relative clause may have a whole sentence as its antecedent rather than a specific noun phrase; for example:

• *The cat was allowed on the bed, which annoyed the dog*.

Here, the context of the sentence (presumably) indicates that which refers not to the bed or the cat but to the entire proposition expressed in the main clause, namely the circumstance that the cat was allowed on the bed. Such constructions are discouraged in formal usage and in texts written for nonnative speakers because of the potential for ambiguity in parsing; a construction more accepted in formal usage would be The cat's being [or having been] allowed on the bed annoyed the dog.

Finite and Non-Finite

Relative clauses may be either finite clauses (as in the examples above) or non-finite clauses. An example of a non-finite relative clause in English is the infinitive clause on whom to rely, in the sentence "She is the person on whom to rely".

Relative Clauses in English

In English, a relative clause follows the noun it modifies. It is generally indicated by a relative pronoun at the start of the clause, although sometimes simply by word order. If the relative pronoun is the object of the verb in the relative clause, it comes at the beginning of the clause even though it would come at the end of an independent clause ("He is the man whom I saw", not "He is the man I saw whom"). The choice of relative pronoun can be affected by whether the clause modifies a human or non-human noun, by whether the clause is restrictive or not, and by the role (subject, direct object, or the like) of the relative pronoun in the relative clause.

• For a human antecedent, "who", "whom", or "that" is usually used ("He is the person who saw me", "He is the person whom I saw", "He is the person that I saw"). For a non-human antecedent, only "that" or "which" is used.
• For a non-human antecedent in a non-restrictive clause, only "which" is used ("The tree, which fell, is over there"); while either "which" or "that" may be used in a restrictive clause ("The tree which fell is over there", "The tree that fell is over there")—but some styles and prescriptive grammars require the use of "that" in the restrictive context.
• Of the relative pronoun pair "who" and "whom", the subjective case form ("who") is used if it is the subject of the relative clause ("He is the policeman who saw me"); and, in formal usage, the objective case form ("whom") if it is the object of the verb or preposition in the relative clause ("He is the policeman whom I saw", "He is the policeman whom I talked to", "He is the policeman to whom I talked"); but in informal usage "whom" is often replaced by "who".

In English, non-restrictive relative clauses are set off with commas, but restrictive ones are not:

• "I met a man and a woman yesterday. The woman, who had a thick French accent, was very pretty." (non-restrictive—does not narrow down who is being talked about)
• "I met two women yesterday, one with a thick French accent and one with a mild Italian one. The woman who had the thick French accent was very pretty." (restrictive—adds information about who is being referred to)The status of "that" as a relative pronoun is not universally agreed.

Simple Present

The simple present or present simple is a form that combines present tense with "simple" (neither perfect nor progressive) aspect.

In the indicative mood it consists of the base form of the verb, or the -s form when the subject is third-person singular (the verb be uses the forms am, is, are). However, with non-auxiliary verbs it also has a periphrastic form consisting of do (or third-person singular does) with the bare infinitive of the main verb — this form is used in questions (and other clauses requiring inversion and negations, and sometimes for emphasis.

The principal uses of the simple present are given below.

To refer to an action or event that takes place habitually. Such uses are often accompanied by frequency adverbs and adverbial phrases such as always, often, from time to time and never.
Examples:

• I always take a shower.
• He writes for a living.

This contrasts with the present progressive, which is used for actions taking place at the present moment.

With stative verbs in senses that do not use progressive aspect, to refer to a present or general state, whether temporary, permanent or habitual. (In senses that do use progressive aspect, the present simple is used when the state is permanent or habitual.)

• You are happy.
• I know what to do.
• Denmark lies to the north of Germany.

When quoting someone or something, even if the words were spoken in the (usually very recent) past:

• The label says "External use only".
• Mary says she's ready.

To refer to a single completed action, as in recounting the events of a story in the present tense (see historical present), and in such contexts as newspaper headlines, where it replaces the present perfect:

• In Hamlet, Ophelia drowns in a stream.

• 40-year-old wins gold medal.

Sometimes to refer to an arranged future event, usually with a reference to time:

• We leave for Berlin tomorrow at 1 pm.

  In providing a commentary on events as they occur, or in describing some theoretical sequence of events:

• I chop the chives and add them to the mixture.

• According to the manager's new idea, I welcome the guests and you give the presentation.

In many dependent clauses referring to the future, particularly condition clauses, clauses expressing place and time, and many relative clauses (see below):

• If he finds your sweets, he will eat them.
• We will report as soon as we receive any information.

In certain situations in a temporal adverbial clause, rather than the present progressive:

• We can see the light improving as we speak.

In colloquial English it is common to use can see, can hear for the present tense of see, hear, etc., and have got for the present tense of have (denoting possession.

See have got and can see below.

For the present subjunctive, see subjunctive.

For uses of modal verbs (which may be regarded as instances of the simple present) see modal verbs.

Present progressive

The present progressive or present continuous form combines present tense with progressive aspect. It thus refers to an action or event conceived of as having limited duration, taking place at the present time. It consists of a form of the simple present of be together with the present participle of the main verb and the ending -ing.

• We are cooking dinner now.

This often contrasts with the simple present, which expresses repeated or habitual action (We cook dinner every day). However, sometimes the present continuous is used with always, generally to express annoyance about a habitual action:

• You are always making a mess in the study.

Certain stative verbs do not use the progressive aspect, so the present simple is used instead in those cases. The present progressive can be used to refer to a planned future event:

• We are tidying the attic tomorrow.

It also appears with future reference in many condition and time clauses and other dependent clauses:

• If he's sleeping when you arrive, wake him up.
• I will finish the job while the children are playing.

It can also refer to something taking place not necessarily at the time of speaking, but at the time currently under consideration, in the case of a story or narrative being told in the present tense (as mentioned above under present simple):

• The king and queen are conversing when Hamlet enters. For the possibility of a present subjunctive progressive, see English subjunctive.

Present Perfect

The present perfect (traditionally called simply the perfect) combines present tense with perfect aspect, denoting the present state of an action's being completed, that is, that the action took place before the present time. (It is thus often close in meaning to the simple past tense, although the two are not usually interchangeable.) It is formed with the present tense of the auxiliary have (namely have or has) and the past participle of the main verb.

The choice of present perfect or past tense depends on the frame of reference (period or point in time) in which the event is conceived as occurring. If the frame of reference extends to the present time, the present perfect is used. For example:

• I have written a letter this morning. (if it is still the morning)
• He has produced ten plays. (if he is still alive and professionally active)
• They have never traveled abroad. (if they are still alive and considered capable of traveling)

If the frame of reference is a time in the past, or a period that ended in the past, the past tense is used instead. For example:

• I wrote a letter this morning (it is now afternoon);
• He produced ten plays (he is now dead or his career is considered over, or a particular past time period is being referred to);
• They never traveled abroad (similarly).

See Simple past for more examples.

The simple past is generally used when the occurrence has a specific past time frame – either explicitly stated (I wrote a book in 1995; the water boiled a minute ago), or implied by the context (for example, in the narration of a sequence of events). It is therefore normally incorrect to write a sentence like I have written a novel yesterday; the present perfect cannot be used with an expression of past time such as yesterday.

With already or yet, traditional usage calls for the present perfect: ''Have you eaten yet? Yes, I've already eaten. However, current informal American speech tends to use the simple past: Did you eat yet? Yes, I ate already.''

Use of the present perfect often draws attention to the present consequences of the past action or event, as opposed to its actual occurrence. The sentence she has come probably means she is here now, while the simple past she came does not. The sentence, "Have you been to the fair?" suggests that the fair is still going on, while the sentence, "Did you go to the fair?" could mean that the fair is over. (See also been and gone below.) Some more examples:

• I have eaten. (implies that I'm no longer hungry)
• We have made the dinner. (implies that the dinner is now ready to eat)
• The weather has gotten cloudier. (implies that it is now more cloudy than previously)

It may also refer to an ongoing state or habitual action, particularly in saying for how long, or since when, something is the case. For example:

• I have lived in Paris for five years.
• He has held the record since he won his Olympic gold.
• We have eaten breakfast together every morning since our honeymoon.

This implies that I still live in Paris, that he still holds the record and that we still eat together every morning (although the first sentence may also refer to some unspecified past period of five years).

When the circumstance is temporary, the present perfect progressive is often appropriate in such sentences (see below); however, if the verb is one that does not use the progressive aspect, the basic present perfect is used in that case too:

• Amy has been on the swing for ten minutes.

The present perfect may refer to a habitual circumstance, or a circumstance being part of a theoretical or story narrative being given in the present tense (provided the circumstance is of an event's having taken place previously):

• Whenever I get home, John has usually already arrived.
• According to the plan, the speeches have already been given when the cake is brought out.

The present perfect may also be used with future reference, instead of the future perfect, in those dependent clauses where future occurrence is denoted by present tense. For example:

• When you have written it, show it to me.

Present Perfect Progressive

The present perfect progressive (or present perfect continuous) construction combines some of this perfect progressive aspect with present tense.

It is formed with the present tense of have (have or has), the past participle of be (been), and the present participle of the main verb and the ending "-ing"

This construction is used for ongoing action in the past that continues right up to the present or has recently finished:

• I have been writing this paper all morning.
• Why are his eyes red? He has been crying.

It is frequently used when stating for how long, or since when, something is the case:

• She has been working here since 1997.
• How long have you been sitting there?
• They have been arguing about it for two weeks.

In these sentences the actions are still continuing, but it is the past portion of them that is being considered, and so the perfect aspect is used. (A sentence without perfect aspect, such as I am sitting here for three hours, implies an intention to perform the action for that length of time.)

With stative verbs that are not used in the progressive, and for situations that are considered permanent, the present perfect (nonprogressive) is used instead.

B2 / Upper Intermediate

A CEFR B2 level English language user is considered to be at Upper intermediate level. A B2 level English language user is expected to have the following abilities:

• Can understand the main ideas of complex text on both concrete and abstract topics, including technical discussions in their field of specialization.
• Can interact with a degree of fluency and spontaneity that makes regular interaction with native speakers quite possible without strain for either party.
• Can produce clear, detailed text on a wide range of subjects and explain a viewpoint on a topical issue giving the advantages and disadvantages of various options.
• Can understand a wide range of demanding, longer texts, and recognize implicit meaning.
• Can express themselves fluently and spontaneously without much obvious searching for expressions.
• Can use language flexibly and effectively for social, academic and professional purposes.
• Can produce clear, well-structured, detailed text on complex subjects, showing controlled use of organizational patterns, connectors and cohesive devices.

In summary, at B2 level, English language users are expected to have a high level of fluency and comprehension, with the ability to understand and produce complex language. They should be able to communicate effectively in a variety of settings, both social and professional. They should be able to use the language flexibly and with a high degree of accuracy.

B2 | Upper Intermediate.

Difficulty: Medium

Medium difficulty. Difficulty levels represent author's opinion about how hard a question or challenge is.