Used to

This is a practical oversimplification which will be right most of the time. For more detailed information see Mastery of the Tenses!
Main Uses for the Used to
"used to do"

For past actions that don't happen now
  • I used to smoke.
  • She used to work here.
For past states that are no longer true.
  • He used to live here.
  • They used to have a dog called Rover.