`1`. He hasn't gone abroad before.

- This is the first time + S + have/has + Vpp

= S + have/has + not + Vpp + before.

`2`. She has learned French for 1 month.

- S + started _ Ving + thời gian + ago

= S + have/has + Vpp + for + khoảng thời gian

`3`. We have eaten since it started to rained.

- S1 + began + Ving + when + S2 + started + to V

= S1 + have/has + Vpp + since + S2 + started + to V

`4`. I haven't had my hair cut since I left home. 

- S + last + V2/ed + when + S2 + V2/ed

= S1 + have/has + not + Vpp + since + S2 + V2/ed

`5`. She hasn't talked to me for 5 months.

- The last time + S + V2/ed + was + thời gian + ago

= S + have/has + not + Vpp + for + khoảng thời gian