Ответ:

  1. What were you doing at six o’clock on 2 May?
  2. Yes, I was watching TV.
  3. I wasn’t working that day.
  4. She was making dinner in the kitchen.
  5. She was cooking my favourite pizza.
  6. They were doing their homework upstairs in their bedrooms.
  7. She was standing in the kitchen with my wife.
  8. They were talking.

Past Continuous образуется с помощью was/were и глагола с окончанием -ing; для отрицания используется wasn’t/weren’t.