1.I have never seen him before.
2. I have been studying English for 3 years.
3. I last saw him when I left school.
4. It has been raining for 2 days.
5. She is the most beautiful girl I have ever met.
6. It's the coldest winter that they had ever had
7. She hasn't kissed me for 5 months.
8. We haven't met for a long time.
9. How long have you had it?
10. She has been driving for 1 month.
S+started/began+Ving+time ago = S+ have/has + been + Ving+ for/since time
The last time + S+ V(qkđ) = S+ have/has not + V3/ed
How long + mệnh đề hiện tại hoàn thành
Since+ mốc thời gian
For+ khoảng thời gian
This is the first time+ S+V(qkđ/qkht) = S+have/has (not)+V3/ed+before