Auxiliaries 

It’s very common to use to have or to be as auxiliaries or helping verbs. For example: 

• Have you seen that film? (a form of to have plus a past participle) 
• I haven’t had a chance to go to the store today. (a form of to have plus a past participle) 
• Are you learning a lot of new words? (a form of to be plus a present participle) 
• She isn’t studying for her exams. (a form of to be plus a present participle) 

But there are other auxiliary verbs that are used with infinitives (to go, to run, to help, to find, and so on). 

Note that many of these special verbs cannot be used in all tenses. And in some cases, you have to change to a different verb to form a specific tense. The examples that follow will be conjugated with the third person pronoun he. 

	Present	Past	Present Perfect	Past Perfect	Future	Future Perfect
TO BE ABLE TO	is able to	was able to	has been able to	had been able to	will be able to	will have been able to
TO BE SUPPOSED TO	is supposed to	was supposed to	has been supposed to	had been supposed to	will be supposed to	will have been supposed to
CAN	can	could orwas able to	has been able to	had been able to	will be able to	will have been able to
TO HAVE TO	has to	had to	has had to	had had to	will have to	will have had to
MAY	may	might	—	—	—	—
MUST	must	had to	has had to	had had to	will have to	will have had to
OUGHT TO	ought to	—	—	—	—	—
SHOULD	should	—	—	—	—	—
TO WANT	wants	wanted	has wanted	had wanted	will want	will have wanted
TO NEED TO	needs to	needed to	has needed to	had needed to	will need to	will have needed to

Exercise 1 Rewrite the following sentences in the tenses given. Use the pre-ceding examples to help you maintain accuracy. Notice that these sentences con-tain auxiliaries, and remember that not all the tenses can be formed with someof these verbs.

1. Present _________________________________________________________________________________

Past Martin wanted to buy acar. 

Present Perfect _________________________________________________________________________________

Past Perfect _________________________________________________________________________________

Future _________________________________________________________________________________

2. Present _________________________________________________________________________________

Past I was supposed to go home by eight o’clock.. 

Past Perfect _________________________________________________________________________________

3. Present May I try on your newcoat? 

Past _________________________________________________________________________________

4. Present She is not able to visit you today. 

Past _________________________________________________________________________________

Present Perfect _________________________________________________________________________________

Past Perfect _________________________________________________________________________________

Future _________________________________________________________________________________

5. Present _________________________________________________________________________________

Past _________________________________________________________________________________

Present Perfect Have you had to study before the test? 

Past Perfect _________________________________________________________________________________

Future _________________________________________________________________________________

Future Perfect_________________________________________________________________________________

 

Auxiliaries are followed by a verb in its infinitive form minus the particle word to. Look at these examples with the infinitive to work. 

able to work                   ought to work                     can work 

have to work                  supposed to work               must work 

need to work                   may work 

want to work                    should work 

When you use one of the auxiliaries with a verb, you tell to what degree of obligation someone has to carry out the action of the verb. Look at the following sentences. The first one shows the least degree of obligation. This is something someone doesn’t have to do. The last sentence shows the greatest degree of obligation. This is something that someone absolutely must do. 

We may return the books. (Least obligation. It’s our choice.) 

We can return the books. (Little obligation. It’s our choice.) 

We are able to return the books. (Little obligation. We have the ability to do this.) 

We need to return the books. (Slight obligation.) 

We ought to return the books. (Little obligation. But this would be a good idea.) 

We should return the books. (Little obligation. But this would be a good idea.) 

We are supposed to return the books. (Some obligation. Someone has suggested we do this.) 

We must return the books. (Greatest obligation. It is our duty to do this.) 

We have to return the books. (Greatest obligation. It is our duty to do this.) 

When you add an auxiliary to a sentence, you should use the same tense as the original verb. For example: “John found [past tense] a good book.” When you add have to to that sentence, you say, “John had to [past tense] find a good book.” 

Exercise 2

Exercise 2.1 Rewrite the following sentences with the auxiliaries given. Be sure to retain the same tense as in the original sentence. 

1. James borrows a book from Maria. (to want to) 
2. I found some extra money. (to need to) 
3. Mr. Sanchez leaves his luggage at the door. (must) 
4. Did you already speak English as a child? (can) 
5. We haven’t written the whole assignment. (to be able to) 
6. You helped me. (to be supposed to) 
7. The children are careful. (ought to) 
8. Why do they live in that little apartment? (should) 
9. I have often traveled to Europe. (to want to) 
10. Nick reads all the books on the top shelf. (may) 
11. We will take the train as far as Chicago. (to have to) 
12. They spoke with very little accent. (to be able to) 
13. Do you help the child tie his shoes? (can) 
14. The designers turn their work in on time. (to be supposed to) 
15. Will Victor work overtime tomorrow? (to have to)

Exercise 2.2 Remove the auxiliaries from the following sentences and rewrite them appropriately. Maintain the same tense as in the original sentence. 

1. We don’t want to go to the movies. 
2. He shouldn’t eat so fast. 
3. After supper we needed to take a little nap. 
4. Tomorrow I’ll have to go shopping for a new hat. 
5. Why must you always lie to me? 
6. Theresa hasn’t been able to help her grandmother this week. 
7. The guests may leave their coats at the door. 
8. Vera was supposed to get everyone a little gift. 
9. If you need to contact me after nine o’clock, call this number. 
10. At what time should we go for lunch? 

Exercise 2.3 Fill in the blanks in the following sentences with any appropriate auxiliary of your choosing. 

1. We                 go to the opera. 
2. Roberto              play soccer with aneighborhood team. 
3. Why                     it rain every Saturday? 
4. During the summer her family always                    go swimming. 
5. The boy never                   deliver the newspaper on time. 
6. The old man                   walk very carefully. 
7. These men and women                           learn several languages. 

Exercise 2.4 Complete each sentence that follows with any appropriate phrase. 

1. Tomorrow I need to 
2. Should Raquel 
3. After work we were supposed 
4. Her boyfriend ought 
5. My parents have always wanted to 
6. Next week I’ll need to 
7. May I 
8. Tom shouldn’t . 
9. Yesterday I wasn’t able to 
10. I’ve often needed to