7. Past Simple — yesterday logic

• Regular verbs: add -ed.
  work → worked, play → played
• Irregular verbs: a different word — must be memorized.
  go → went, eat → ate, see → saw
• Questions and negatives use did / didn't + base verb (no -ed):
  Did you go? I didn't see him.

Cheat: once 'did' appears, the main verb goes back to its plain form.