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.)

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.

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...).

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.

C2 / Proficiency

A CEFR C2 level English language user is considered to be at Proficiency level. A C2 level English language user is expected to have an even higher level of proficiency than a C1 level user. They are expected to have the following abilities:

• Can understand with ease virtually everything heard or read.
• Can express themselves spontaneously, very fluently and precisely, differentiating finer shades of meaning even in more complex situations.
• Can use the language effectively and appropriately in their professional and academic life.
• Can produce clear, well-structured, detailed text on complex subjects, showing controlled use of organizational patterns, connectors, and cohesive devices.
• 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.

At C2 level, English language users are expected to have a near-native level of proficiency. They should have a mastery of the language and have a full range of idiomatic expressions, colloquialism and cultural references. They should be able to understand and produce language with ease, even in highly complex situations. They should be able to communicate with native speakers with fluency, spontaneity and precision, showing an excellent command of the language. They should be able to use the language appropriately and effectively in academic and professional settings.

C2 | Proficiency.

C1 / Advanced

A CEFR C1 level English language user is considered to be at Advanced level. A C1 level English language user is expected to have the following abilities:

• Can understand a wide range of demanding, longer texts, and recognize implicit meaning
• Can express themselves fluently and spontaneously, almost effortlessly.
• 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.
• Can understand specialized articles and longer technical instructions, even when they do not relate to their field.
• Can use the language effectively and appropriately in their professional and academic life.

At C1 level, English language users are expected to have a high level of fluency and comprehension, with the ability to understand and produce complex language with ease. They should be able to communicate effectively in a variety of settings, both social and professional, using the language flexibly and appropriately. They should also be able to understand specialized texts and technical instructions with little difficulty.

C1 | Advanced.

Difficulty: Hard

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