Which question to ask

It should be "Guess what this picture is". It is not grammatically a question and should not normally have a question mark.

If I use: can you guess what this picture is. Should I use a question mark? I think not!

What is this picture?.... Is a direct question.. where as the other is indirect.. Am I correct?

AnonymousIf I use: can you guess what this picture is. Should I use a question mark? I think not!

You think wrong. 'Can you...?' is a distinct question. And it is not indirect. An indirect question looks like this:

I asked him if he could guess what that picture was.

So if I want to make it a question, it'll be: Can you guess what is this picture?

Am I right?

AnonymousSo if I want to make it a question, it'll be: Can you guess what is this picture?Am I right?

No: Can you guess what this picture is?

So with out 'can you'..... It is not a question.
by adding 'can you' to guess what this is.. It is turned into a question?

Then, is 'guess what that picture is' a question?

Anonymousdirect question ... indirect

What to you mean by that?

A teacher said that this should not be followed by a question mark: guess what this picture is.
Another teacher said that with 'can you' it should be followed by a question mark: can you guess what this picture is.

Does adding 'can you' change it into a question?

AnonymousWhat to you mean by that?

Did you read CJ's link? It is more information about indirect questions.

AnonymousA teacher said that this should not be followed by a question mark: Guess what this picture is.

Right. It is an imperative sentence, not an interrogative sentence

AnonymousAnot