Practice Makes Perfect

Auxiliary Verbs

You have already encountered three auxiliary(or helping) verbs:

be, do, and have. They are conjugated and used with another verb to

change that verb’s meaning or tense:

I go I amgoing (changed to in progress or incomplete)

you sing doyou sing? (changed to a question)

she makes  she hasmade (changed to the present perfect

tense)

There are several other auxiliary verbs you should know. Note that

many of the auxiliary verbs cannot be used in all tenses. And in

some cases, you have to change to a different verb to form a spe-

cific tense. The following examples will be conjugated with the

third-person pronoun he:

to be able to to be supposed to

Present is able to is supposed to

Past was able to was supposed to

Present Perfect has been able to has been supposed to

Past Perfect had been able to had been supposed to

Future will be able to will be supposed to

Future Perfect will have been able to will have been

supposed to

can to have to

Present can has to

Past could OR had to

was able to

Present Perfect has been able to has had to

Past Perfect had been able to had had to

Future will be able to will have to

Future Perfect will have been able to will have had to

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Unit 6

03 (044-061) Units 6-9 11/3/04 1:41 PM Page 44

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