Present perfect progressive

This article describes the uses of various verb forms in the English language. This includes:

The uses considered include expression of tense (time reference), aspect, mood and modality, 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 certain other particular topics, see the articles listed in the adjacent box.

A typical English verb may have five different inflected forms:

The 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.).

For full details of how these inflected forms of verbs are produced, see English verbs.

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. For example:

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 § Perfect and progressive nonfinite constructions 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. As the last example shows, the words making up these combinations do not always remain consecutive.

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