1. It's week since you last tidied this room.
→ S + have/ has + not + V3/ed + for + khoảng thời gian: Ai đó không làm gì trong bao lâu
= It’s + time + since + S + last + V2/ed
2. We have looked for a flat for 2 months and we are still looking.
→ S + began / started + to V/ V-ing + time + ago : bắt đầu làm gì
= S + have/has + V3/ed+ for + khoảng thời gian
since + mốc thời gian
3. I haven't been to a night club before.
→ This is the first time + S + have/has + V3/ed: Lần đầu làm gì
= S+ have/ has + not+ V3/ed+ before
4. This is the first time they have heard such a thing.
→ S + have/ has + never + V3/ed+ before: Ai đó chưa từng làm gì trước đây
= This is the first time + S + have/has + V3/ed:
5. This is the first time his authory has been challenged.
→ No one has challenged his authory = His authory hasn't been challenged
* bị động HTHT: S + have/has (not) + been + V3/ed + (by+O)
