Question

you may speak politely to the elders. correct error​

Answer 1

You should speak polietely to elders

Answer 2

You must speak politely to the elders.

EXPLANATION:

‘May’ is used when there is a possibility of happening. It is based on facts and experiences. Example: we may go on a family trip. This line indicates that there are chances of going on a trip.

There are modal words in English grammar. They are may, might, can, could, must, shall, should, etc., In the given sentence ‘speaking politely to the elders’ is a compulsive thing. So we cannot use ‘may’.

It shows that we may speak politely to the elders if we want. But as it is a compulsive thing we must use either ‘must’ or ‘should’. Should is also used for compulsive kind of sentence.