`-` `\text{S + used to + V :}` Đã từng

`-` `\text{S + didn't use to + V :}` Không từng

`-` `\text{Did + S + use to + V ? :}` Đã từng `?`

`1`.used to play

`2`.didn't use to have

`3`.Did they use to ?

`4`.used to be

`5`.didn't use to like

`6`.did ... use to go ?

`7`.used to be

`8`.didn't use to like

`9`.used to go

`10`.used to live

`\text{@ TheFox}`

`@Tran`

CÔNG THỨC "used to": 

`(+)` S + used to + `V_1`

`(-)` S + didn't + use to + `V_1`

`(?)` Did + S + use to + `V_1` ?

`"Câu 1:used to play"`

`"Câu 2: didn't use to have"`

`"Câu 3: Did they use to work"`

`"Câu 4: used to be"`

`"Câu 5: didn't use to like"`

`"Câu 6: did you use to go"`

`"Câu 7:used to be "`

`"Câu 8: didn't use to like"`

`"Câu 9: used to go"`

`"Câu 10: used to live "`