used
v.v. to have done something regularly in the past, but you do not do it anymore. It can also describe a state that was true before but has changed.
v. to have performed an action habitually or existed in a state in the past. This form is restricted to the past tense and functions as a marginal modal to indicate discontinued habits or states.
I used to live in a small apartment.
She used to play the piano every day after school, but she stopped when she started university.
The building that now serves as a modern art gallery used to be a busy factory where hundreds of local residents found employment during the industrial boom.
From Middle English used, equivalent to use + -ed.
Always followed by the 'to' infinitive. In negative and interrogative forms, the 'd' is often dropped ('did not use to' or 'did you use to'), though 'used not to' is found in formal British English.
I am used to wake up earlyI am used to waking up earlyWhen 'used to' means 'accustomed to', it is followed by a gerund (-ing), not the base form of the verb.