A verb shows an action, an occurrence, or a state of being. ESL writers need to pay special attention to their use of verb tenses, helping or modal verbs (also called auxiliary verbs), and verbs followed by an infinitive or a gerund.

Verb tenses express time. They indicate when an action occurs, occurred, or will occur. The following sections will help you understand and form the simple, perfect, and progressive tenses.

The simple tenses are used to show clear and simple time relationships. The accompanying box summarizes how each of the simple tenses is formed and used.

The perfect tenses are also used to show time relationships. A verb in one of the perfect tenses indicates an action that was or will be completed by or before some specified time. The perfect tenses are constructed by using a form of have along with the verb’s past participle. The box above summarizes how each of the perfect tenses is formed and used.

The simple progressive tenses describe actions in progress, indicating that an action did, does, or will continue. They are formed by using a form of be along with the present participle.

The perfect progressive tenses are used to describe actions that continue to the present or until another action takes place. They are often used to emphasize the length of time involved. The box below summarizes how the progressive and perfect progressive tenses are formed and used.

Helping verbs are used before main verbs to form certain tenses. Some helping verbs—have, do, and be—change form to indicate tense (see 27a). The helping verb do indicates tense in questions, inverted phrases, and negative sentences. Do you know her? Little did I realize what would happen. She does not like him. It is also used for emphasis: The sentence does need a comma. The forms of these helping verbs are as follows.

have, has, had

be, am, is, are, was, were, being, been

do, does, did

Other helping verbs, called modals, do not change form. Modals include can, could, may, might, must, shall, should, will, and would. They are used to express ability, necessity, permission, intention, and so forth. The box below summarizes the common uses of modals.

Often, you will need to use an infinitive or a gerund as the object of a verb in a sentence, as in the following examples.

When you use an infinitive or a gerund as an object, you need to remember that some verbs are followed by infinitives, some verbs are followed by gerunds, and some can be followed by either form without a change in meaning. The following guidelines will help you determine which form to use.

Some verbs, including the verbs listed here, are usually followed by an infinitive in English.

In general, use these verbs with an infinitive, not a gerund.

Some verbs are followed by a noun or a pronoun and then by an infinitive. These verbs include allow, cause, convince, hire, instruct, order, remind, tell, and warn.

When using a negative word (such as no or not) in a sentence containing a verb followed by an infinitive, place the word carefully; its position in the sentence often affects meaning.

She never mentioned it.

She said she did not know.

The causative verbs have, let, and make are followed by a noun or a pronoun and the base form of the verb (without the word to).

The following verbs are often followed by a gerund.

Use these verbs with a gerund, not an infinitive.

In a sentence containing a gerund, place a negative word (such as no or not) between the verb and the -ing form.

Some verbs (such as begin, continue, like, and prefer) can be followed by an infinitive or a gerund with little or no change in meaning.

Other verbs (such as forget, remember, stop, and try) can be followed by either an infinitive or a gerund, but the meaning of the sentence changes.