Answer the question in a complete sentence:

Est-ce que vas au theatre?

If you post your answer, we'll be glad to check it for you.

i am not sure what it says.

What do you think it says?

Are they going to the theatre?

I think you've left out a word. Please check

You're almost right. Did you leave out the word "tu?"

Is it "Are you going to the theatre?"

Yes, if the word "tu" is in the sentence.

How will you answer this question?

Oui, je suis.

That's o.k. But I think your teacher would like you to say, Yes, I'm going to the theater.

How do you say that in French?