To talk about past habits and states we use the verb USED TO.
Affirmative: SUBJ + USED TO + VERB
I used to live on the same street when I was a child.
Negative: SUBJ + DIDN’T + USE TO + VERB / SUBJ + NEVER + USE TO + VERB
I didn’t use to wear winter clothes in Brazil. / I never used to wear winter clothes in Brazil.
Question: DID + SUBJ + USE TO + VERB?
Did you use to have a pet when you were younger?
The pronunciation of the verb USED TO never changes, no matter if it’s in affirmative, negative or interrogative form.
You can practice USED TO with the following exercises: