Use used to + the base form of the verb to discuss past situations, conditions, or habits which are now different or finished.
Note: "Used to" is pronounced as one word: useta [yooz-ta].

Examples:
▶ Sara used to live in New York, but now she lives in Chicago.
▶ Jason used to cook dinner every night, but now he gets takeout several times a week.
▶ Our mailman used to come at 11 a.m. every day, but now he comes later.
▶ Bill used to be a smoker.

=> With questions and negatives, the "d" on "used" is dropped.
Note: "Use to" is pronounced as one word: useta [yooz-ta].

Examples:
▶ Did you use to play football every Saturday?
▶ Did Jeff use to ride his bike to work?
▶ Susan didn't use to believe in ghosts.
▶ I didn't use to like apples, but now I eat one every day.

Use used to + -ing form of the verb to describe something that you are in the habit of doing.

Examples:
▶ I'm used to cooking dinner every night.
▶ I'm used to driving an hour to work.
▶ I'll never get used to living so far from downtown.
▶ We're used to sleeping in* on Sundays.

* sleep in - to sleep late on purpose (and not because you forgot to set your alarm!)