Past Continuous vs Simple Past

1. Use the past continuous for an action that was in progress at a specific time in the past.

• Fabiana started her homework at 8:00. She stopped at 10:00 to go out with friends. At 9:00 she was doing her homework.

2. Use the past continuous and the simple past together when one action interrupts another.

• Fabiana was doing her homework when her friends called and asked her out for a drink.

3. Use the past continuous for the action that started first and the simple past for the interupting action in two way.

• I was living in San Francisco when a big earthquake happened.
• A big earthquake happened while I was living in San Francisco.

4. When two past actions are in progress at the same time in the past.

• I was living in San Francisco while my boyfriend was living in Seattle.