- She cooked yesterday.
- She was cooking at three o’clock yesterday.
- She was cooking from two till four o’clock yesterday.
- I was not reading at five o’clock.
- I was not reading when you came in.
- What was he doing when I came?
- What was he doing the whole day yesterday?
- Pete watered flowers in the garden yesterday.
- Pete was watering flowers in the garden at five o’clock yesterday.
- What was Pete doing when I came to see him?
Past Simple обозначает завершённое действие в прошлом, а Past Continuous — действие, происходившее в определённый момент или период в прошлом.