Be used to, get used to, used to

Be used to + noun phrase or verb-ing (in this pattern used is an adjective and to is a preposition).

I am used to getting up early in the morning. I don't mind it.
He didn't complain about the noise nextdoor - he was used to it.

If you are used to something, you have often done or experienced it, so it's not strange, new or difficult for you.

The opposite of be used to is be not used to.

I am not used to the new system yet.

Get used to + noun phrase or verb-ing (in this pattern used is an adjective and to is a preposition).

I got used to getting up early in the morning.

After a while he didn't mind the noise in the office - he got used to it.

If you get used to something, you become accustomed to it.
It is the process of becoming used to something.

Used to + verb refers to a habit or state in the past. It is used only in the past simple.

Past habits
If you used to do something, you did it for a period of time in the past, but you don't do it any more.

We used to live there when I was a child.
I used to walk to work everyday when I was younger.

Past states
We also say used to to express a state that existed in the past but doesn't exist now. States are not actions. They are expressed using stative verbs such as have, believe, know and like.

I used to like The Beatles but now I never listen to them.
He used to have long hair but nowadays his hair is very short.

The form of the question is
did(n't) + subject + use to be.
The form of the negative is
subject + didn't + use to be.

Did(n't) he use to work in your office?
We didn't use to be vegetarians.