Use of 'do' in interrogative of Present tense

Question

We say that "Do we have class today?"

Can we say that "Do there is class today?".Or,we must say "Is there class today?".

Answer 1

We never use do when making a question about a sentence that uses to be. When you make a question about a to be statement, you use to be in the question.

For example,
He is tall. : Is he tall?
NOT
Does he is tall?

or

There is class today. : Is there class today?
NOT
Does there is class today? (or Do there is class today?)

We only use do when making a question about a sentence that uses another verb that isn't be, have, shall, will, may, must, or can.

For example:
He drinks beer. : Does he drink beer?