1)this is the first time l have been stupid?
=>  I have never been stupid before 
2)the last time l talked to him was 5 weeks ago
=> I haven't talked to him for 5 years 
3)hệ began phaying football 3 years ago
=> He has played football for 3 years 
4)when did you buy your car?
=>How long have you bought that car ?
5)l last took a bath a week ago
=>  I haven't taken a bath for a week