1-It explains the action which occurred in a continuous manner in the past and is over now
It was raining the morning
2-expresses speaker’s intention to perform an action in the past
He was going to the market when the bell rang
Positive sentence
subject + was/were + v1st form + ing + object
She was singing a song last night.
They were playing cricket.
Negative sentence
subject + was/were + not + v1st form + ing + object
He was not studying yesterday.
You ere not present in the class yesterday.
Interrogative sentence
was/were + subject + v1st form + object
Was he fighting with his friends?
Were the children crying?