It is easy to make yes/no questions using ‘be’ in the present tense and present continuous tense.

‘Inverting’ the order

In the present tense and present continuous tense, the verb ‘be’ looks like this:

I am
You are
He is
She is
It is
We are
They are
Some are
Many are

To make a question, swap the word order:

Am I going?
Are you happy?
Is he your boyfriend?
Is she tall?
Is it a cat?
Are we playing?
Are they OK?
Are some red?
Are many people there?

Answers

The answer uses the original word order:
Is he going?
(Yes, he is / No, he isn’t)

Are you OK?
(Yes, I am / No, I’m not)

Add question words for details

English has question words:

what
why
when
where
which
who
how
how many
how long

These are added to make different questions:

What is his name?
When are we going?
Where is your car?
Which are your shoes?
Who are they?
How is your food?
How long is the game?
How many are there?