Habitual behaviour in the past

The past simple is used for regular actions or habitual behaviour in the past, often with a frequency adverb:
I hardly ever went away on holiday when I was young.

Used to + infinitive is used to refer to past habits and situations which no longer occur or exist now:
We used to have a dog, but he died last year.

Note: the negative and question forms:
I didn't use to like pizza. Where did you use to study?

Note: use to cannot express present habitual behaviour. I usually (not use to) play basketball once a week.

Would + infinitive is used to refer to past habits, but not past situations:
Habit: My mother would often read to me when I was a young boy.
Situation: I used to (not would) have a bicycle.

Stative verbs such as have (possession), be, live, like, believe, think (= have an opinion), understand and know are not used with would to refer to the past.