`1`. They haven't talked to each other for two months.

`2`. She hasn't seen her elder sister since 1999.

`3`. It's years since she last wrote to me.

`4`. It's ten years since Robert and Catherine were married.

`5`. They haven't cleaned their room for two weeks.

_______________________________________________________________

`@` Quá khứ đơn: S + V2 + thời gian + ago

→ Hiện tại hoàn thành: S + have/has + V3 + for + thời gian.

`@`  It's + khoảng thời gian + since + S + V-QKĐ: Đã bao lâu kể từ khi 

`@` Thì hiện tại hoàn thành :

`+` Khẳng định : S + have/ has + V3/ed + (object)

`+` Phủ định : S + have/ has + NOT +  V3/ed + (O)

`+` Nghi vấn : Have/ Has + S + V3/ed + (object)?

Trả lời:

Yes, S+ have/ has.

No, S + haven’t/ hasn’t.

`+` Câu hỏi Wh- question :

When/Where/Why/What/How + have/ has + S + (not) + V3/ed + (O)?

CHÚC BẠN HỌC TỐT!~