Used to

This usage is highly useful to express actions that happened in the past, but no longer happen.

• He used to play cricket a lot but he doesn't play very often now.
• A: Do you go to the cinema very often?
• B: Not now, but I used to.
• I used to travel a lot. But now-a-days I have no time to do so.

Used to.....( for something that was true but is not true any more) .

• They used to be very rich, but after they failed in their business they are quite badly off.
• This building is now a cinema. It used to be an auditorium.
• She used to have very long hair when she was in standard VII.
• They used to live in a small village but now they are in a big town.
• There used to be many mango trees. Now there is only one.

Note :- Used to do something' is past, and it is not used in the present form. The normal question form is 'Did (you) use to.................?

• A: Did you use to eat a lot of sweets when you were a child?
• B: I didn't use to.

The negative form is ' Didn't use to (used not to .....is also possible)

• I didn't use to like him.

OR . I used not to like him.