4. I've just finished my project.
I haven't had my medicine yet.
I've already scheduled a meeting for tomorrow.
5. a)
A: Have you ever made a snowman?
B: Yes, I have.
A: Have you ever ridden a horse?
B: No, I haven't.
A: Have you ever spoke to a famous person?
B: No, I haven't.
A: Have you ever went to India?
B: Yes, I have.
A: Have you ever drove a car?
B: No, I haven't.
A: Have you ever ate caviar?
B: Yes, I have.
b) Jennifer has made a snowman.
Jennifer has never ridden a horse.
Jennifer has never spoken to a famous person.
Jennifer has went to India.
Jennifer has never driven a car.
Jennifer has ate caviar.
