As for me, I would use Complex Object with "see": I was able to see the students doing their homework. I was able to see the students do their homework.

Hi... yes both are correct depending what you want to say...

Go Steve =)

"I was able to see how the students did their homework" is correct. "I was able to see how the students do their homework" is also correct, as long as you weren't talking about that specific point in time and the students still do their homework the same way.

"I was able to see how the students DID their homework" It's "did" because "was' it also in the sentence and that means it's past tense. if you were to use the word 'do' in a sentences similar to that it would be. "I want to see how the students are able to do their homework"