E
Modal verbs
There are nine modal auxiliaries (will, would, can, could, shall, should, may, might, must). They are followed by an infinitive without to. In addition, some other verbs (semi-modals) work in a similar way to these modal verbs. These include: have to, need to, ought to.
Subject questions
We make questions by putting the subject between the auxiliary verb and the main verb:
auxiliary verb subject verb
Have you finished your report?
If there is no auxiliary verb in the affirmative (ie present simple and past simple) add do/does/did.
Do you like beer?
We put the subject after the verb in questions with be.
Are you British?
If the question word (who, what, which) is the subject of the verb, we put the verb after the subject, as in a normal statement. We do not use do/does/did with the present simple or past simple.
Who gave you the key?
What happened to your car?