Complete the text with the correct past, present, or future forms of able to?

Complete the text with the correct past, present, or future forms of able to. The reason I love talking about fashion is because I’m studying it at college. I take some night classes about clothing as well. One of the things I’ve learned is how to knit. I (16) _____________ (not able to) do that until a few months ago. I (17) _____________ (not able to) sew yet. Hopefully, I (18) _____________ (able to) do that in about a week when my sewing class starts. It’s going to be three days a week, on Monday, Wednesday, and Friday. Unfortunately, I (19) _____________ (not able to) go on Wednesdays because I have classes at college that day. When I asked about the possibility of changing my schedule at college last week, I (20) _____________ (not able to) do it without changing other classes too. You’re probably wondering why I spend so much time taking courses and studying, right? Shouldn’t I be out having fun? Well, the truth is when you do something you love, you’re having fun all the time. That’s how I feel about life right now.