complete the sentences with can. can't, will be able to, won't be able to,could couldn't

Конечно, я помогу! Давайте начнем.

1. Я ______ understand this difficult math problem if you explain it to me.
2. Tomorrow, I ______ go to the museum with my friends because I have a lot of homework to do.
3. Last year, I ______ swim, but this year I learned and now I love it.
4. We ______ finish the project on time if we work together efficiently.
5. I ______ believe I got an A on my history exam!
6. She said she ______ speak fluent Spanish after living in Madrid for a year.
7. I ______ go to the concert with you because I have plans already.

Дайте мне знать, что вы думаете о предложенных завершениях предложений!