`-` Cấu trúc "used to":

`@` used to: đã từng `->` Diễn tả một hành động xảy ra thường xuyên trong quá khứ và không tiếp tục ở hiện tại

`@` Công thức:

$(+) S + used$ $to + Vinf$

$(-) S + did$ $not/didn't + use$ $to + Vinf$

$(?) Did + S + use$ $to + Vinf?$

`1.` I didn't use to like flying, but I love it now.

`2.` We used to be friends, but we don’t get on now.

`3.` Did John use to work for IBM before he came here?

`4.` Winters didn't use to be as cold as they are now.

`5.` She used to live with her mother, but now she lives with her father.

`6.` What did you use to be like when you were a child?

`7.` I used to wear very thick glasses, and I used to be quite short.

`8.` What did you use to do for fun?

`9`. We didn't use to have phones or technology of any kind.

`10.` Did you use to get good marks in school?

`1)` didn't use to like 

`2)` used to be 

`3)` Did John use to work 

`4)` didn't use to be 

`5)` used to live 

`6)` did you use to be 

`7)` used to wear `-` used to be 

`8)` did you use to do 

`9)` didn't use to have 

`10)` Did you use to get 

`@` Cấu trúc 

`(-)` \({\text{ S + didn't use to + V(nguyên thể)...}} \)

`(+)` \({\text{ S + used to + V(nguyên thể)...}} \)

`(?)` \({\text{ Did + S + use to + V(nguyên thể)...?}} \)