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

`=>` S`+` hasn't/haven't`+` Vpp `+` ......... `+` before 

`2.` She has driven for 1 month.

`=>`  S`+`has/have `+` Vpp `+` for/since `+` .......

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

`=>`  S`+` started/began `+` to V/V-ing `+` .... `+` when/on/in/ago `+` ....

`=>`  S`+`has/have `+` Vpp `+` for/since `+` .......

Các công thức đổi HTHT - QKĐ

Structure 1: 

S + has/have + V3/ed + for/since + time 

--> S + started / began + to V / Ving 

--> It is / has been + time + since + S+ V2/ed 

Structure 2: 

S + has/have + not/never + V3/ed + ... before

--> This/It is the first time + S+ has/have+ V3/ed

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16. He hasn't gone abroad before.

17. She has driven for 1 month.

18. We have eaten since it started to rain.

`color{orange}{~MiaMB~}`