It is impossible to compose a correct sentence without using a proper verb. The verb is at the very foundation of a sentence. The verb phrase may be composed of only one word or it may have related parts. Consider the following examples.
- Angela had to go to Chicago.
- The boys are fishing at the creek.
- Someone should repair that window.
Sometimes, the related parts are composed of more than one word. In the examples above, the verbs are go, fish, and repair, and the related parts are had to, are, and should.
Some sentences contain a single verb (for example, go), while other sentences include a related part before the main verb (for example, a form of be + a form of the verb go). Auxiliary verbs are among the related parts that can form a verb phrase; in some grammar books, they are called “helping verbs.” The second example below illustrates the verb be used as an auxiliary.
- She goes to class.
- She is going to class.
The first sentence contains a form of the single verb go. In the second example, however, the sentence also contains the verb go, but this time it has a related part, the auxiliary verb is, which precedes the verb in its present participle form (is going).
Auxiliary verbs change how a verb is used. Such changes can affect the tense, mood, or even the meaning of the verb.
The auxiliary be can be used in any tense, and in every tense the main verb is in the form of a present participle.
|PRESENT||She is fixing that old clock.|
|PAST||She was fixing that old clock.|
|PRESENT PERFECT||She has been fixing that old clock.|
|PAST PERFECT||She had been fixing that old clock.|
|FUTURE||She will be fixing that old clock.|
The auxiliary verb have is used with a past participle to form the present perfect or past perfect tense.
- She has lived here all her life.
- They have been working on the problem all day.
- Martin had never seen a kangaroo before.
- She had been napping when the fire broke out.
The auxiliary do/did is used with a basic verb to form a question, a negative statement with not, or an emphatic statement. Do is used in the present tense, and did in the past tense.
- Do you understand Arabic?
- Did Mr. Keller sell that old car yet?
- You don’t have enough money to buy that CD.
- You’re wrong. I do have enough money.
- But you did not have enough money yesterday.
Some auxiliary verbs are called modal auxiliaries. They are used with a verb to show the degree of obligation of the action of the verb. Two important modal auxiliaries are have to and should.
- Do you have to play the radio so loud?
- Mary has to stay at home today.
- Dad, you shouldn’t work so hard in this heat.
- Why should I care?