Learning how to correctly use verbs in the English language can help you avoid making mistakes when communicating through speech or writing. Verbs can be simply defined as "doing" words, which indicate action. Many different rules govern the use of verbs in the English language, such as the rules regarding regular and irregular verbs, subject-verb agreement, active and passive verbs and modal verbs. Learning these rules can ensure you use verbs correctly in speech and writing.

Irregular Verbs

Verbs have five different forms: the infinitive, the simple present, the simple past, the past participle and the present participle. A regular verb is defined as one in which the simple past and the past participle have the same form, which ends in "ed." For example, with the verb "to wash," both the simple past and the past participle form is "washed." Irregular verbs do not have the same word which ends in "ed" as the simple past and past participle. Many different ending forms exist, so no definitive rules can be established. For example, the verb "to swim" has a simple past form of "swam" and a past participle form of "swum." Past participles also require an "auxiliary verb" such as "has" to be used in a sentence. For example, the simple past form of to swim can be used in the sentence "David swam across the river." The past participle form would have to be used in a sentence such as "David has swum across the river."

Subject-Verb Agreement

The subject-verb agreement essentially means that if the singular form of the subject is used, the singular form of any verb must be used when referring to it. Likewise, if a plural subject is being described, a plural verb must be used. The simplest form of this rule governs sentences such as "He smokes," which uses a single subject "he" and the single form of the verb, "smokes." If this sentence was intended to speak about multiple people, the correct form would be "they smoke." This is done by changing the subject to a plural and the verb to the plural form.

Active and Passive

Sentences which include verbs can be presented in either passive or active form. Passive form is used in more formal situations, such as scientific articles, and the active form is used in informal situations. Passive sentences occur frequently in the English language, but the basic rules for when to use them state that they can be used when the action is more important than the person or thing that did it, and when the agent of a particular action isn't known. The passive sentence "German is spoken in the classroom" has an active counterpart of "We speak German in the classroom."

Modal Verbs

Use modal verbs when you need to express ability to do something, when you are requesting permission to do something or when you are obligated to do something. The modal verb "can" implies the ability to complete a particular task, such as "I can correctly use modal verbs." It can also be used to indicate probability or grant permission. "May" is used to request permission to do something, such as "May I use a modal verb in this sentence?" Finally, "must" is used when you are obligated to do something, such as "you must use a modal verb to state that you are able to do something." "Must" can also be used for other purposes, such as to make a strong recommendation.