Don't talk ___ play in the classroom.

If you choose ( A), it can be interpreted as follows:

1. You can play in the classroom.
2. You can talk in the classroom.

3. But you are warned not to do both of them together in the classroom.

If you choose ( B), it means as follows:

1. You cannot play in the classroom.
2. You cannot talk in the classroom.

panda fold 627I wonder why we can't choose (A).

Because the speaker means B. Of course, A makes sense and is grammatical, but it can be construed as talking and playing at the same time. Also, nobody would use "and" in saying that, and "or" defaults to inclusive. Bear in mind that if you are to select one answer to a multiple-choice question, it is supposed

It's always a good idea to suspect that 'or' is needed with negations.

I don't want any chicken or lamb.
Don't disturb the wasps or hornets.
She doesn't like orange or turquoise dresses.

CJ