`1`. The editor last wrote to Mai a month ago.
`->` S + have/has + not + Vpp + for + khoảng thời gian
`=` S + last + V2/ed + thời gian + ago
`2`. How long have you ridden a bicycle ?
`->` How long have/has + S + Vpp ?
`3`. He hasn't met her since he left school.
`->` The last time + S + V2/ed + was + when + S2 + V2/ed
`=` S + have/has + not + Vpp + since + S2 + V2/ed
`4`. They began studying computer 2 years ago.
`->` S + began + Ving + thời gian + ago
`5`. This is the first time she has been abroad.
`->` This is the first time + S + have/has + Vpp