Công thức used to (đã từng):
(+) S + used to + V1
(-) S + didn't use to + V1
(?) Did + S + use to + V1?
--------------------------------------------------
1. We used to live in a flat when I was a child.
2. People didn't use to have mobile phones 20 years ago.
3. Did Jim use to go swimming every weekend?
4. My father didn't use to smoke, but he gave up five years ago.
5. Lily didn't use to cook much, but now she makes dinner every day.
6. There used to be a supermarket on the corner
7. People didn't use to buy so much stuff as they do today.
8. Did you use to play football or basketball at school?
9. I used to go to bed very late but not anymore!
10. Which TV programme did you use to watch the most when you were little?
color{orange}{~STMIN~}