21. Mary ought to cook it for them……………………………?
22. That was Ann on the phone………………………?
23. The Smiths need two cars………….……?
24. He used to eat raw fish………….………?
25. You`d better wait for Bill………………?

`@`$\color{#ff978c}{Mai}\color{#ff92f5} {Tuấn}\color{#b080ff}{Dũng}$

21. Mary ought to cook it for them, oughtn't she?

22. That was Ann on the phone, wasn't it?

23. The Smiths need two cars, don't they?

24. He used to eat raw fish, didn't he?

25. You'd better wait for Bill, hadn't you?

_________________________________________________________________________________________________

công thức :

- kđ:

+  S + verb + …, láy đuôi?

Vd: You are coming to the my birthday, aren't you?

- pđ:

+ S + verb(not) + …, láy đuôi?

Vd: She isn't a policewomen, **is she?

21. oughtn't she

22. wasn't it

23. don't they

24. didn't he

25. hadn't you/shouldn't you

$-----$

`=>` S `+` V `+` O, trợ động từ `+` đại từ chủ ngữ của S`?`