I am able to do this homework for an hour. - I have to stop doing this homework after an hour has passed. It's too difficult, for example, or it gives me a headache. I need to stop after an hour, and then I can continue with it again later.
I am able to do this homework in an hour. - I do not need more than an hour to finish this homework.
I am able to do this homework in an hour. - I can finish this homework within the specified time frame of an hour. I don't need more than an hour. The time it takes me to finish this homework will not exceed one hour. ________________________________60 minutes|in an hour
I am able to do this homework for an hour. - I can only dedicate an hour of time to this homework, and then I have to stop. This homework can only possess, use, or consume an hour of my time.
This is my homework's hour._____one hour____
It can't have anymore time. I can only give it an hour.
Student or Learner