Have you just eaten a candy?
a- Yes, I´ve just eaten a candy.

Did you read that book?
b- No, I didn´t read that book.

How much have you spent (on it)?
c- I´ve spent $1,000.

What did you buy?
d- I bought sweets.

Has she done this exercise yet?   (Ojo, en las preguntas usamos palabra  ´´yet´´)
e- Yes, she´s already done this exercise.

When did she do it?
f- She did it last week