posted by rfvv .
What do you think he is doing?
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?)
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.