Исправьте ошибки 1.which hat is this? -it's jack's 2.i have been a dancer for 2010 3.he hasn't washed the car already 4.joe didn't used to have short hair when he was a teenager

1. WHOSE hat is this?-It's Jack's
2. I have been a dancer SINCE 2010
3. He hasn't washed the car YET.
4. Joe didn't USE to have short hair when he was a teenager.