=>
1. My husband didn't use to do homework but now he does.
2. Children didn't use to play with high-tech devices at early age but now they do.
3. The students didn't use to go to school by public transportation but now they do.
4. My city used to be a tourist destination but now it isn't.
5. Traffic jam didn't use to happen when I was small but it happens now.
6. My mother used to work at a restaurant 3 years ago but now she doesn't.
7. He used to be the President of Student Union but now he isn't.
8. There used to be many tree-lined streets in my hometown but now there is none of them.
Used to V : đã từng
(+) S used to V
(-) S didn't use to V
(?) Did S use to V?

$\text{1.}$ My husband didn't use to do homework but now he does.
$\text{2.}$ Children didn't use to play with high-tech devices at early age but now they do.
$\text{3.}$ The students didn't use to go to school by public transportation but now they do.
$\text{4.}$ My city used to be a tourist destination but now it isn't.
$\text{5.}$ Traffic jam didn't use to happen when I was small but it happens now.
$\text{6.}$ My mother used to work at a restaurant 3 years ago but now she doesn't.
$\text{7.}$ He used to be the President of Student Union but now he isn't.
$\text{8.}$ There used to be many tree-lined streets in my hometown but now there is none of them.

→ S + used to + V-inf + O 

→ S + didn't (did not) + use to + V-inf + O 

→ Did + S + use to + V-inf + O ? 

→ Used to diễn tả 1 hành động hay 1 sự việc nào đó đã xảy ra trong quá khứ nhưng nay đã chấm dứt hoàn toàn , ko xảy ra nữa 

$\text{@Keisha}$