Use “used to/didn’t use to” + base form of a verb for actions that happened repeatedly/regularly/as a routine in the past but are not true now.
I used to wear glasses when I was a child.
I used to grow pigeons when I was a teenager.
I used to go to disco clubs when I was in my 20’s.
Important: Just remember that when you make a negative statement or form a question, the verb ‘use’ must be in its base form.
I didn’t use to have a cell phone.
I didn’t use to play with girls.
I didn’t use to travel outside of Romania.
Did you use to travel a lot?
Did she use to like horror movies?
Did they use to go to parties together?
You can also use simple past instead of "used to/didn’t use to". (Example: I grew pigeons when I was a teenager). That’s because the Simple Past tense also indicates actions that happened repeatedly/regularly/as a routine in the past.
A common mistake is to use "used to" for present habits. For present habits use Present Simple + usually.
Note: "would + base form" can be used for the same purpose.
When I was a child, I would [often] visit my grandparents who lived very close to our house.
When it was my birthday, they would give me money instead of other presents.
However, you must remember that, grammatically, you cannot use "would" instead of "used to" with state words, but you can use both with other verbs.
We used to live in Sweden when I was a child. (NOT: We would live ...)
live in Sweden
visit my grandparents