`1.` I have not met Mrs Brown for over ten years.

`->` It + is/has been + thời gian + since + S + (last) + Ved

`=` S + haven't/hasn't + PII + for + thời gian

`2.` Our car has already been cleaned by my father.

`->` Bị động HTHT (`+`) : S + have/has + been PII (by O)

`->` Our car là N số ít, dùng Has

`1.` I have not met Mrs. Brown for over ten years.

`-` It is + time + since + S + (last) + V2/ed: Đã bao lâu kể từ khi ai làm gì

`-` HTHT: `(-)` S + have/has + not + V3

`-` For + Khoảng thời gian

`2.` Our car has already been cleaned by my father.

`-` HTHT: `(+)` S + have/has + V3

`-` Bị động: `(+)` S + have/has been + V3 + (by O)