Verb

Verbs constitute one of the main word classes in the English language. Like other types of words in the language, English verbs are not heavily inflected. Most combinations of tense, aspect, mood and voice are expressed periphrastically, using constructions with auxiliary verbs.

Generally, the only inflected forms of an English verb are a third person singular present tense form in -s, a past tense, a past participle (which may be the same as the past tense), and a form ending in -ing that serves as a present participle and gerund. Most verbs inflect in a simple regular fashion, although there are about 200 irregular verbs; the irregularity in nearly all cases concerns the past tense and past participle forms. The copula verb be has a larger number of different inflected forms, and is highly irregular.

A typical English verb may have five different inflected forms:

• The base form or plain form (go, write, climb), which has several uses—as an infinitive, imperative, present subjunctive, and present indicative except in the third-person singular
• The -s form (goes, writes, climbs), used as the present indicative in the third-person singular
• the past tense or preterite (went, wrote, climbed)
• The past participle (gone, written, climbed) – this is identical to the past tense in the case of regular verbs and some irregular ones (here the first two verbs are irregular and the third regular)
• The -ing form (going, writing, climbing), used as a present participle, gerund, and (de)verbal nounThe verb be has a larger number of different forms (am, is, are, was, were, etc.), while the modal verbs have a more limited number of forms.

Some forms of be and of certain other auxiliary verbs also have contracted forms ( 's, 're, 've, etc.).

In English, verbs frequently appear in combinations containing one or more auxiliary verbs and a nonfinite form (infinitive or participle) of a main (lexical) verb.

Examples

The first verb in such a combination is the finite verb, the remainder are nonfinite (although constructions in which even the leading verb is nonfinite are also possible – see below). Such combinations are sometimes called compound verbs; more technically they may be called verb catenae, since they are not generally strict grammatical constituents of the clause.

• The dog was barking very loudly.
• My hat has been cleaned.
• Jane does not really like us.

As the last example shows, the words making up these combinations do not always remain consecutive.

Tenses, Aspects and Moods

The means English uses for expressing the three categories of tense (time reference), aspect and mood are somewhat conflated. English has only limited means for expressing these categories through verb conjugation, and tends mostly to express them periphrastically, using the verb combinations mentioned in the previous section. The tenses, aspects and moods that may be identified in English are described below (although the terminology used differs significantly between authors). Note that in common usage, particular tense–aspect–mood combinations such as "present progressive" and "conditional perfect" are often referred to simply as "tenses".

Infinitive

Regarding English, the term infinitive is traditionally applied to the unmarked form of the verb when it forms a non-finite verb, whether or not introduced by the particle to.

Hence sit and to sit, as used in the following sentences, would each be considered an infinitive:

• I can sit here all day.
• I want to sit on the other chair.

The form without to is called the bare infinitive; the form introduced by to is called the full infinitive or to-infinitive.

The other non-finite verb forms in English are the gerund or present participle (the -ing form), and the past participle – these are not considered infinitives.

Moreover, the unmarked form of the verb is not considered an infinitive when it is forms a finite verb: like a present indicative ("I sit every day"), subjunctive ("I suggest that he sit"), or imperative ("Sit down!"). (For some irregular verbs the form of the infinitive coincides additionally with that of the past tense and/or past participle, like in the case of put.)

Certain auxiliary verbs are defective in that they do not have infinitives (or any other non-finite forms).

This applies to the modal verbs (can, must, etc.), as well as certain related auxiliaries like the had of had better and the used of used to. (Periphrases can be employed instead in some cases, like (to) be able to for can, and (to) have to for must.) It also applies to the auxiliary do, like used in questions, negatives and emphasis like described under do-support. Infinitives are negated by simply preceding them with not.

Of course the verb do when forming a main verb can appear in the infinitive. However, the auxiliary verbs have (used to form the perfect) and be (used to form the passive voice and continuous aspect) both commonly appear in the infinitive: "I should have finished by now"; "It's thought to have been a burial site"; "Let him be released"; "I hope to be working tomorrow."

Perfect Infinitive

There are nonfinite constructions that are marked for perfect, progressive or perfect progressive aspect, using the infinitives, participles or gerunds of the appropriate auxiliaries. The meanings are as would be expected for the respective aspects: perfect for prior occurrence, progressive for ongoing occurrence at a particular time. (Passive voice can also be marked in nonfinite constructions – with infinitives, gerunds and present participles – in the expected way: (to) be eaten, being eaten, having been eaten, etc.)

Examples of nonfinite constructions marked for the various aspects are given below.

Bare infinitive:

• You should have left earlier. (perfect infinitive; for similar constructions and their meanings see modal verbs)
• She might be revising. (progressive; refers to an ongoing action at this moment)

• He must have been working hard. (perfect progressive; i.e. I assume he has been working hard)

To-infinitive:

• He is said to have resigned. (perfect infinitive)
• I expect to be sitting here this time tomorrow. (progressive)
• He claims to have been working here for ten weeks. (perfect progressive)

Present participle:

• Having written the letter, she went to bed. (perfect)
• The man having left, we began to talk. (perfect, in a nominative absolute construction)
• Having been standing for several hours, they were beginning to feel tired. (perfect progressive)

Past participle:

• We have been waiting a long time. (progressive, used only as part of a perfect progressive construction)

Gerund:

• My having caught the spider impressed the others. (perfect)
• We are not proud of having been drinking all night. (perfect progressive)

Other aspectual, temporal and modal information can be marked on nonfinite verbs using periphrastic constructions. For example, a "future infinitive" can be constructed using forms such as (to) be going to eat or (to) be about to eat.

Auxiliary Verb

In English grammar, certain verb forms are classified as auxiliary verbs. Exact definitions of this term vary; an auxiliary verb is generally conceived as one with little semantic meaning of its own, which modifies the meaning of another verb with which it co-occurs. In English, verbs are often classed as auxiliaries on the basis of certain grammatical properties, particularly as regards their syntax – primarily whether they participate in subject–auxiliary inversion, and can be negated by the simple addition of not after them.

Certain auxiliaries have contracted forms, such as -'d and -'ll for had/would and will/shall. There are also many contractions formed from the negations of auxiliary verbs, ending in n't (a reduced form of not). These letter contractions can participate in inversion as a unit (as in Why haven't you done it?, where the uncontracted form would be Why have you not done it?), and thus in a certain sense can be regarded as auxiliary verbs in their own right.

An auxiliary verb is most generally understood as a verb that "helps" another verb by adding grammatical information to it. On this basis, the auxiliary verbs of English may be taken to include:

• forms of the verb do (do, does, did), when used with other verbs to enable the formation of questions, negation, emphasis, etc.;
• forms of the verb have, when used to express perfect aspect;
• forms of the verb be, when used to express progressive aspect or passive voice;
• the modal verbs, used in a variety of meanings, principally relating to modality.

The following are examples of sentences containing the above types of auxiliary verbs:

• Do you want tea? – do is an auxiliary accompanying the verb want, used here to form a question.
• He had given his all. – had is an auxiliary accompanying the past participle given, expressing perfect aspect.
• We are singing. – are is an auxiliary accompanying the present participle singing, expressing progressive aspect.
• It was destroyed. – was is an auxiliary accompanying the past participle destroyed, expressive passive voice.
• He can do it now. – can is a modal auxiliary accompanying the verb do.

However the above understanding of auxiliary verbs is not always strictly adhered to in the literature, particularly in the case of forms of the verb be, which may be called auxiliaries even when they do not accompany another verb. Other approaches to defining auxiliary verbs are described in the following sections.

There is a group of English verbs which have certain special grammatical (syntactic) properties that distinguish them from other verbs. This group consists mainly of verbs that are auxiliaries in the above sense – verbs that add grammatical meaning to other verbs – and thus some authors use the term auxiliary verb, in relation to English, to denote precisely the verbs in this group. However, not all enumerations of English auxiliary verbs correspond exactly to the group of verbs having these grammatical properties. This group of verbs may also be referred to by other names, such as special verbs.

The principal distinguishing properties of verbs in this special group are as follows:

• They can participate in what is called subject–auxiliary inversion, i.e. they can swap places with the subject of the clause, to form questions and for certain other purposes. For example, inversion of subject and verb is possible in the sentence They can sing (becoming Can they sing?); but it is not possible in They like to sing – it is not correct to say Like they to sing? (instead do-support is required: Do they like to sing?).
• They undergo negation by the addition of not after them. For example, one can say They cannot sing, but not They like not to sing (again do-support is required: They don't like...).
• Other distinct features of verbs in this group include their ability to introduce verb phrase ellipsis (I can sing can be shortened to I can in appropriate contexts, whereas I like to sing cannot be shortened to I like), and the positioning of certain adverbs directly after them (compare I can often sing with I often like to sing).

The group of verbs with the above properties consists of:

• the finite indicative forms of the verb be: am, is, are, was, were;
• the finite indicative forms of the verb have: have, has, had, principally when used to make perfect verb forms;
• the finite indicative forms of the verb do: do, does, did, when used to provide do-support;
• the principal modal verbs can, could, may, might, must, shall, should, will, would;
• certain other verbs, sometimes but not always classed as modals: ought; dare and need in certain uses; had in had better; and sometimes used in used to (see the relevant sections of modal verbs for details).

If membership of this syntactic class is considered to be the defining property for auxiliary verbs, it is therefore the above-listed verbs that will be considered as auxiliaries.

Additionally, non-indicative and non-finite forms of the same verbs (when performing the same functions) are usually described as auxiliaries too, even though all or most of the distinctive syntactical properties do not apply to them specifically.

This concerns be (as infinitive, imperative and subjunctive), being and been; and when used in the expression of perfect aspect, have, having and had.

The chief difference between this syntactic definition of auxiliary verb and the functional definition given in the section above is that the syntactic definition includes the verb be even when used simply as a copular verb, in sentences like I am hungry and It was a cat, where it does not accompany any other verb.

Sometimes, non-auxiliary uses of have follow auxiliary syntax, as in Have you any ideas? and I haven't a clue.

Other lexical verbs do not do this in modern English, although they did so formerly, and such uses as I know not... can be found in archaic English.

Lists or sets of auxiliary verbs in English, as given by various authors, generally consist of most or all of the verbs mentioned in the above sections, though with minor discrepancies.

The main differences between the various proposed sets of auxiliary verbs are noted below.

• For the reasons mentioned above, forms of the verb be may or may not be regarded as auxiliaries when used as a copula not accompanying any other verb.
• The verb ought is sometimes excluded from the class of auxiliaries (specifically the modal auxiliaries) on the grounds that, unlike the principal modals, it requires the to-infinitive rather than the bare infinitive.
• The verbs dare and need are not always considered auxiliaries (or modals); their auxiliary-like syntactic behavior (and their modal-like invariance) applies only to some instances of these verbs, e.g., dare and need.
• The verbs had and used in the expressions had better and used to are not always included among the auxiliaries or modals; in the case of used to questions and negations are in any case more frequently formed using do-support than with auxiliary syntax.
• Other verbs with modal-like or auxiliary-like function may sometimes be classed as auxiliaries even though they do not have auxiliary-like syntactic behavior; this may apply to have in the expression have to, meaning must.

As mentioned below, the contractions of negated forms of auxiliary verbs (isn't, shouldn't, etc.) behave in a certain sense as if they were auxiliaries in their own right, in that they can participate as a whole in subject–auxiliary inversion.

Meaning Contribution

Forms of the verbs have and be, used as auxiliaries with a main verb's past participle and present participle respectively, express perfect aspect and progressive aspect. When forms of be are used with the past participle, they express passive voice. It is possible to combine any two or all three of these uses: The room has been being cleaned for the past three hours. Here the auxiliaries has, been and being (each followed by the appropriate participle type) combine to express perfect and progressive aspect and passive voice.

The auxiliary do (does, did) does not necessarily make any meaning contribution, although it can be used to add emphasis to a clause. This is called the emphatic mood in English. An example of this use is found in "I do go to work on time every day." Also, Do does help in the formation of questions, negations, etc.

Other auxiliaries – the modal verbs – contribute meaning chiefly in the form of modality, although some of them (particularly will and sometimes shall) express future time reference. Their uses are detailed at modal verbs article, and tables summarizing their principal meaning contributions can be found in the articles on modal verb and auxiliary verb.

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.

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.

B1 / Intermediate

A CEFR B1 level English language user is considered to be at an intermediate level. A B1 level English language user is expected to have the following abilities:

• Can understand sentences and frequently used expressions related to areas of most immediate relevance (e.g. very basic personal and family information, shopping, local geography, employment).
• Can communicate in simple and routine tasks requiring a simple and direct exchange of information on familiar and routine matters.
• Can describe in simple terms aspects of their background, immediate environment and matters in areas of immediate need.
• Can understand the main points of clear standard input on familiar matters regularly encountered in work, school, leisure, etc.
• Can produce simple connected text on topics that are familiar or of personal interest.
• Can describe experiences and events, dreams, hopes & ambitions and briefly give reasons and explanations for opinions and plans.

At B1 level, English language users are expected to have a basic level of proficiency in the language. They should be able to understand and produce language in simple and routine tasks, and be able to communicate in familiar and routine matters. They should be able to understand the main points of clear standard input on familiar matters and be able to produce simple connected text on topics that are familiar or of personal interest. They are able to express themselves with a degree of fluency, but with some hesitation, and occasional errors in grammar and vocabulary.

B1 | Intermediate.

Difficulty: Hard

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