used to

/ juːst /

adjective

1. made familiar with; accustomed to

   I am used to hitchhiking

verb

1. takes an infinitive or implied infinitive used as an auxiliary to express habitual or accustomed actions, states, etc, taking place in the past but not continuing into the present

   I used to fish here every day

   I don't drink these days, but I used to

Usage

The most common negative form of used to is didn't used to (or didn't use to ), but in formal contexts used not to is preferred