`@` Công thức thì quá khứ đơn:

`+` Cấu trúc:

`(+)` Khẳng định: S + Ved/V2 

`(-)` Phủ định: S + didn't + V-inf...

`(?)` Nghi Vấn: Did + S + V-inf....?

`+` với tobe

`-` khi tobe là was thường đi với những chủ ngữ ở dạng số ít: I/ It/ she/ he/ N(danh từ số ít)

`-` khi tobe là were thường đi với những chủ ngữ ở dạng số nhiều: they/ we/ you/ N(Danh từ số nhiều)

________________________________________________________________

Đáp án: (chữ in đậm)

`1.` `-` They were in Rio last summer.

`=>`  `(-)` They weren't  in Rio last summer.

          `(?)`  Did they be in Rio last summer ?

`2.` `-` We did our exercise this morning.

`=>` `(-)` We didn't our exercise this morning.

        `(?)` Did We do our exercise this morning?

`3.` `-` My parents came to visit me last July.

`=>` `(-)` My parents didn't come to visit me last July.

        `(?)` Did My parents come to visit me last July?

`4.` `-` The hotel was very expensive.

`=>` `(-)` The hotel wasn't very expensive.

        `(?)` Did the hotel be very expensive?

`5.` `-` I had a bicycle when I was young.

`=>` `(-)` I didn't have a bicycle when I was young.

        `(?)` Did you have a bicycle when I were young?

`6.` `-` The children went to the zoo yesterday.

`=>` `(-)` The children didn't go to the zoo yesterday.

        `(?)` Did the children go t to the zoo yesterday?

`7.` `-` Emie ate the last doughnut.

`=>` `(-)` Emie didn't eat the last doughnut.

        `(?)` Did Emie eat the last doughnut?

`8.` `-` They bought a new house last month.

`=>` `(-)` They didn't buy a new house last month.

        `(?)` Did they buy a new house last month?