43 He hasn't written to me for 3 months.

44  I haven't been abroad since the summer of 1978.

45  That house hasn't been lived in for ten years.

46 I last saw him 2 months ago.

47  The last time we went to a concert was over a year ago.

Công thức : 

S + has/have + Vpp + since/for + thời gian

( He hasn't written to me for 3 months và I haven't been abroad since the summer of 1978.)

S + last + Ved/d + was + thời gian.

( I last saw him 2 months ago.)

The last time + S + Ved/d + was + thời gian

(The last time we went to a concert was over a year ago.)

43. It's 3 months since he wrote to me.

⇒ He hasn't written to me for 3 months.

44. The last time I was aboard was in the summer of 1978.

⇒ I haven't gone aboard since the summer of 1978.

45. It's ten years since that house was lived in.

⇒ That house has been lived in for ten years.

46. I haven't seen him for 2 months.

⇒ I last saw him 2 months ago.

47. I haven't been to a concert for over a year.

⇒ The last time I went to a concert  was in over a year.