Question

what is modal auxiliary ?

Answer 1

heping verb or auxiliary verb such as will, shall, may, might, can, could, must, ought to, should, would, used to, need are used in conjuctions with main verb to help in making sentences.
these words not have meaning of itself.
ex:-
I will have been studying chemistry for ten years.
here will have been auxiliary verb
and studying main verb.

He should be here by now.
I could swim quite well when I was younger.
You might have discussed it with me first.

Answer 2

Modals : Mood showing helping verbs.
Modal Auxiliaries : These are the types of help verbs. These are used with other helping verbs.
Modal Auxiliaries : can/could, may/might, must/ought to, shall/should, will/would.
1. Can ; shows the mood of power. example : he CAN lift the box.
2. Could ; shows the mood of past time. example : he COULD not walk.
3. May ; it is used in formal request, it shows the mood of polite request or permission. example : MAY i come in.
4. Might ; shows the mood of less possibility. example : It MIGHT rain today.
5. Must/ought to ; shows the mood of duty. example : you MUST pay your taxes.
6. Shall ; mood of promise, intention, determination. example : he SHALL go.
7. Should ; it shows mood of suggestion or advice. example : you SHOULD complete your home work.
8. Will : shows the mood of determination, promise, wish, willingness, request.
example : i WILL help you.
9. Would ; mood of past tense. example : She told me that she WOULD come some day.