Question

Pick out the modern auxilary and state its function
Could you have done it?​

Answer 1

Explanation:

Would is the model auxiliary used here.

hope this will help you a lot

Answer 2

The modal auxiliary in the given sentence 'Students must be punctual in their work. ' is must. Here, the modal auxiliary 'must' denotes the necessity to do something. Cambridge English Dictionary defines 'must' as 'used to show that it is necessary or very important that something happens in the present or future.

no I don't do