Used to + infinitive
Here I will give a short , clear and simple explanation of how used to + infinitive is used in English
Used to is a form that we use to talk about an habitual action in the past that we don’t do now.
The structure is in the past so questions and negatives are formed using “did”
- I used to live in London (now I don’t live in London)
- John used to play rugby every weekend (now he doesn’t play because he has serious knee problems)
- Mary didn’t use to speak French (but now she speaks French very well because she has lived in Toulouse for 5 years)
- Did you use to have a lot of homework when you went to Primary school?
For a general introduction to the differences between the variations of use look at: