Used to: States and Repeated Situations

To talk about past states we may use “used to”:

I used to live in Berlin when I was a student. (I don’t live there anymore.)
I didn’t use to be a programmer at that company. (This wasn’t true.)

To talk about repeated situations in the past we can also use “used to”:

We used to visit our parents every weekend. (We don’t do it anymore.)
She didn’t use to attend daily meetings. (Now she does.)

We can use “used to” only for past states and actions that don’t happen now. Moreover, we can’t use “used to” to talk about single past events:

I used to have lunch yesterday at 12:00.
I used to have lunch every day at 12:00.

Remember, to form sentences with “used to” we use the infinitive form of the main verb. Have look at the examples below:

Positive Sentences:
When I was younger I used to get up early every Sunday.
She used to live with her parents when she was a student.
There used to be a smoking lounge in our office.

Negative Sentences:
You didn’t (did not) use to work as a programmer.
He didn’t (did not) use to go to the gym regularly.

Questions:
Did you use to work at the weekends?
Did she use to ride a bike to work?