Auxiliary verbs, also called helping verbs, are used with a main verb to create compound verb forms.
The simple present of the verb BE can be contracted in two ways: with a subject pronoun or with the negative adverb not
The simple present and simple past of the auxiliary verb DO are frequently contracted with the negative adverb not.
This lesson explains how to make contractions with the verb HAVE and a subject pronoun or the negative adverb not.
The phrase could have refers to something that was possible but did not occur in the past. In informal speech, it is contracted to could've , not could of .
This lesson introduces the various forms English uses to indicate the future.
Verbs are the words in a sentence that indicate an action, a state of being, or possession.
A list of the most common irregular English verbs, including their simple past conjugations and present and past participles.
This lesson explains the grammar of modal verbs and where they are placed in a sentence or question.
This lesson explains the meaning of each modal verb and provides example sentences.
The verb BE can be negated with negative adverbs, adjectives, and prefixes.
This lesson explains one of the very important roles of the verb DO: the formation of negative phrases.
The past participle is a verb form that indicates a completed action. It is used in perfect aspects, adverb clauses, and the passive voice.
The past perfect, or pluperfect, is a compound verb form which requires two verbs: had and a past participle.
The past perfect progressive, also called the pluperfect progressive is a compound verb form. It requires three verbs: had + been + verb+ing.