What do you think he is doing?

Question

1. I think he is playing computer games on the computer.

2. I think he is playing a computer game on the computer.

(Which answer is right? Do we have to use the singular form or the plural form?)

Answer 1

If you use the first sentence, you are speaking in general.

If you use the second sentence, you are speaking specifically about what "he" is doing at the moment.