Past Simple/ Past Continuous
1. Something was going on (=past continuous) and was interupted by something else (=past simple).
- Mike had (p.s.) an accident while he was driving (p.c.).
- Rick was sleeping (p.c.) when the teacher shouted (p.s.) at him.
2. You can also use the past continuous when something was really annoying in the past.
- Last year she was always coming to class late.
Past Continuous: was/were + verb+ing
Past Simple: verb-ed (2nd word of the irregular verbs)