The past progressive is used to describe an action that began in the past, continued for a period of time, and then ended in the past. Before you continue, review these lessons: Verb BE | Present participle.
The past progressive, sometimes called the past continuous, is formed with the verb BE conjugated in the simple past (was | were) followed by a present participle. This is the formula: subject + BE + (verb+ing).
The past progressive is often used to describe what was happening at the time something else was happening.
|The sun was setting as we walked along the beach.|
|Susan and Tom were sleeping while I was working.|
The past progressive can also describe what was happening at the time another event interrupted that action.
|As I was reading my book, the power went out.|
|While I was crossing the street, my cell phone rang.|