`1.`It is a week since Mr Hai last smoked.
`→`S + have/has not + Vpp + since/for + time
`=`It is + time + since + S last + V2/ed
`2.`It is the first time I have drunk whisky.
`→`S + have/has never + Vpp + before : chưa từng làm việc gì đó trước đây
`=`It/This is the first time + S + have/has + Vpp