`2.` It's the first time they have (ever) visited Vienna.

`-` CT: It/This is the first time + S + have/has + (ever) + Vpp

`->` Đây là lần đầu tiên ai đó làm điều gì

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

`3.` I haven't eaten out for a long time.

`-` CT: It + tobe + (khoảng thời gian) + since + S + Ved/c2

`->` Đã là bao lâu từ lúc ai đó làm gì

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

`4.` The last time Roger played tennis was six weeks ago.

`-` CT: The last time + S + Ved/c2 + was + (khoảng thời gian) + ago

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

`5.` Mrs Smith has gone on holiday for years.

`-` for years: trong vòng nhiều năm

`6.` The last time John went to his country house was at Easter.

`-` CT: The last time + S + Ved/c2 + was + when + S + Ved/c2/(mốc thời gian)

`->` Lần cuối ai đó làm gì là kể từ khi nào

`=` S + have/has + not + Vpp + since + S + Ved/c2(mốc thời gian)

`->` Ai đó không làm gì kể từ khi nào

`1.` It's the first time they have visited Vienna .

`2.` I haven't eaten out for a long time . 

`3.` The last time Roger played tennis was six weeks ago .

`4.`  Mrs Smith has gone on holiday for years .

`5.` The last time John went to his country house was at Easter .

`@`$\text{Kiến thức :}$

`-` S + last + Ved / V2 + time + ago / in + mốc thời gian / when + clause

`=` S + have / has + not + Ved / V3 + for / since .

`=` It's + time + since + S + last + Ved / V2 .

`=` The last time + S + Ved / V2 + was + time + ago .

`-`  This is the first time + S + have / has + Ved / V3 .

`=` S + have / has + never + Ved / V3 + before .

`-` S + started / began + V-ing / to V + time + ago / in + mốc thời gian / when + clause .

`=` S + have / has + Ved / V3 + for / since .