Uses of English verb forms

Modern standard English has various verb forms, including:

Finite verb forms such as go, goes and went
Nonfinite forms such as go, going and gone
Combinations of such forms with auxiliary verbs, such as was going and would have gone

They can be used to express tense, aspect, mood, modality and voice, in various configurations.
For details of how inflected forms of verbs are produced in English, see English verbs. For the grammatical structure of clauses, including word order, see English clause syntax. For non-standard or archaic forms, see individual dialect articles and thou.

Inflected forms of verbs

A typical English verb may have five different inflected forms:

The base form or plain form, which has several uses—as an [|infinitive], [|imperative], present subjunctive, and present indicative except in the third-person singular
The -s form, used as the present indicative in the third-person singular
The [|past tense] or preterite
The [|past participle] – identical to the past tense in the case of regular verbs and some irregular ones, it may also used as a verbal adjective
The -ing form, used as a [|present participle], [|gerund], verbal noun, and sometimes verbal adjective

The verb be has a larger number of different forms, 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.
For full details of how these inflected forms of verbs are produced, see English verbs.

Verbs in combination

In English, verbs frequently appear in [|combinations] containing one or more auxiliary verbs and a nonfinite form of a main verb. For example:
The first verb in such a combination is the finite verb, the remainder are nonfinite. Such combinations are sometimes called verb catenae. As the last example shows, the words making up these combinations do not always remain consecutive.
For details of the formation of such constructions, see English clause syntax. The uses of the various types of combination are described in the detailed sections of the present article.

Tenses, aspects and moods

As in many other languages, the means English uses for expressing the three categories of tense, aspect and mood are somewhat conflated. In contrast to languages like Latin, though, 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. In common usage, particularly in English language teaching, particular tense–aspect–mood combinations such as "present progressive" and "conditional perfect" are often referred to simply as "tenses".

Tenses

Verb tenses are inflectional forms which can be used to express that something occurs in the past, present, or future. In English, the only tenses are past and non-past, though the term "future" is sometimes applied to periphrastic constructions involving modals such as will and go. Some verb tenses are compound and can combine different verb tenses to form another one.

Present

is used, in principle, to refer to circumstances that exist at the present time and general truths. However the same forms are quite often also used to refer to future circumstances, as in "He's coming tomorrow". For certain grammatical contexts where the present tense is the standard way to refer to the future, see [|conditional sentences] and [|dependent clauses] below. It is also possible for the present tense to be used when referring to no particular real time, or when recounting past events. The [|present perfect] intrinsically refers to past events, although it can be considered to denote primarily the resulting present situation rather than the events themselves.
The present tense has two moods, indicative and subjunctive; when no mood is specified, it is often the indicative that is meant. In a present indicative construction, the finite verb appears in its base form, or in its -s form if its subject is third-person singular. For the present subjunctive, see English subjunctive.

Past

forms express circumstances existing at some time in the past, although they also have certain uses in referring to hypothetical situations. They are formed using the finite verb in its preterite form.
Certain uses of the past tense may be referred to as subjunctives; however the only distinction in verb conjugation between the past indicative and past subjunctive is the possible use of were in the subjunctive in place of was. For details see English subjunctive.

Future

English lacks a morphological future tense, since there is no verb inflection which expresses that an event will occur at a future time. However, the term "future tense" is sometimes applied to periphrastic constructions involving modals such as will, shall, and to be going to.
The morphological present tense can be used to refer to future times, particularly in conditional sentences and dependent clauses.
The morphologically past variants of future modals can be used to create a periphrastic future-in-the-past construction. Here the sentence as a whole refers to some particular past time, but would win refers to a time in the future relative to that past time. See.

Aspects

Simple

"Simple" forms of verbs are those appearing in constructions not marked for either progressive or perfect aspect.
Simple constructions normally denote a single action, as in Brutus killed Caesar, a repeated action, as in I go to school, or a relatively permanent state, as in We live in Dallas. They may also denote a temporary state, 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. It is expressed using the auxiliary verb to be together with the present participle 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 non-progressive forms 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. However its progressive aspect is used in appropriate situations when the verb expresses the passive voice, and when it has the meaning of "behave" or "act as".
The verb to have does not use progressive forms when it expresses possession, broadly understood, but it does use them in its active meanings. See also have got below. 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 are generally used without progressive aspect, although some of them can be used in the progressive to imply an ongoing, often temporary situation, or an activity. See also can see below.
Verbs denoting positional state normally do use the progressive if the state is temporary: ''He is standing in the corner.''
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 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. If such a circumstance is temporary, the perfect is often combined with progressive aspect.
The implications of the present perfect 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 details, see the relevant sections below. For all uses of specific perfect constructions, see the sections below on the present perfect, [|past perfect], [|future perfect], and [|conditional perfect].
By using non-finite forms of the auxiliary have, perfect aspect can also be marked on infinitives, and on participles and gerunds. For the usage of such forms, see the section below on [|perfect and progressive non-finite constructions].
Although all of the constructions referred to here are commonly referred to as perfect, some of them, particularly non-present and non-finite 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 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. For the meanings of such constructions with the various modals, see English modal verbs.

Perfect progressive

The perfect and progressive 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 is used together with been 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.
For uses of specific perfect progressive constructions, see the sections below on the present perfect progressive, past perfect progressive, future perfect progressive, and conditional perfect progressive. For perfect progressive infinitives, participles and gerunds, see.