He may be

He may be in the hall room.
Is this sentence present simple?

Yes, you are just adding ‘may’ (a modal verb) to a present simple sentence to change its meaning from being sure to a possibility.

Modal verbs are followed by infinitives so you have to change ‘is’ (present simple third person singular) to its base form, or infinitive ‘be’.

  1. He is in the hall room. (definite)

  2. He may be in the hall room. (possible).

By the way I have not heard of ‘hall room’. Do you mean ‘hall’.

I mean “hall room”= A room which is fixed for only different seminar and meeting.
thanks a lot for solution----
other questions

  1. Do you mean base form of “is” is “be”?
  2. According to you solution the following solution is also present simple
    He could be there.
    correct?
  1. Yes, that is correct.

  2. That is right. So if you take out ‘could’ it would be ‘he is there’.

if base form of “is” is be then what is the form of “is”?

I’m not too good at naming things, but as far as I’m aware, as i said in my reply to your first post, it is ‘third person singular’ of ‘to be’.

As in:

I = First person singular
We = First person plural
You = Second person singular or plural
He = Third person singular (masculine)
She = Third person singular (feminine)
It = Third person singular (neutral)

They = Third person plural / third person gender-neutral singular

So “he / she / it is…”