Auxiliary Verbs are the verbs be, do, have, will when they are followed by another verb (the full verb) in order to form a question, a negative sentence, a compound tense or the passive.
In this question, " Do you like Czech food?" - nbsp;do is the auxiliary verb, like nbsp;is the main verb.
In questions, auxiliary verbs come before the subject - in our example question, you is the subject.
Auxiliary verbs - Do/does/didDo is used for forming questions and making negatives.
Do is used with the present simple tense.
Does is the form for the 3rd person singular (does she...) and did is the past tense of do .
Do and does is never used for the past.
The verb "be"
The verb be can be used as an auxiliary and a full verb.
Be when it is used as an auxiliary verb is used to form the continuous tense, compound tenses and the passive form .
"Am, is, are" are the present tense for be .
- Am is used for the first person singular (I) Is is used for the 3rd person singular ( he, she, it ). Are is used for the other cases ( you , they and we ).
- Was is the form used for the 1st and 3rd person singular - I, he , she, it .
- Were is the past tense for - you, they and we .
You can tell that in the following sentences be is an auxiliary because it is followed by another verb (the full verb).
(For progressive forms use the "-ing" form of the full verb; for passive voice, use the past participle of the full verb.)
Progressive Forms
- Present Progressive:
- He nbsp;is playing football.
- Past Progressive:
- He nbsp;was playing football.
- Present Perfect Progressive:
- He has been playing football.
- Past Perfect Progressive:
- He had been playing football.
Passive
- Simple Present/Past:
- The house is/was built.
- Present/Past Perfect:
- The house has/had been built.
- Future I:
- The house will be built.
"be" as a full verb
The verb be can also be a full verb. In this case, it's not followed by another verb. If be is used as a full verb, we do not need an auxiliary in negative sentences or questions.
- positive sentence:
- They nbsp;are fifteen years old.
- negative sentence:
- They nbsp;are not fifteen years old.
- question:
- Are they fifteen years old?
The auxiliary verb "have"
Have is used to make the perfect tenses (it is always followed by the past participle - the third form of the verb). The forms of the perfect tense are the present perfect, past perfect and future perfect.
- Has is the form for the 3rd person singular (he, she, it)
- Have is used for all other forms (I, you, we, they).
- Had is the past tense for "have" for all pronouns.
Other auxiliary verbs: can could, may, might, shall, should, will, would and ought to.
These are also known as modal verbs . We use them to show obligation, possibility and necessity.
For example:
- Jack is late. He might be sleeping.(Possibility)
- I should clean my room today.(Obligation)
- I must wear a tie to school.(Necessity)