When do we use "what kinds of..." and "what kind of..." in a sentence?
1. What kinds of books do you read?2. What kind of books do you read?3. What kinds of movies do you watch?4. What kind of movies do you watch?Thanks in advance.

Question

Answer

Never 'What kinds" just 'what kind'

Answer

In the examples you listed, it would be more appropriate to say "what kind". "What kinds" implies that you want to receive multiple answers to your question.