1) Past Continuous Tense is mainly used to tell past actions showing uncertainty about times of starting and finishing.
2) Past Continuous Tense is used to tell persistent past habits; as,
- I was always solving Sudoku.
3) Past Continuous Tense is used to describe something; as,
- A lady was baking a roti and a dog was waiting to have it.
4) Past Continuous Tense is used to explain the development; as,
- It was raining heavily.
- The Sun was rising.