In a previous section, you learned about the present progressive tense. The past progressive is used when talking about something that was in progress at a particular time in the past:

–They were buying groceries when we arrived.

The buying of groceries probably began before and continued after the arrival of we.

TENSE FORMATION (Past Progressive)

Simply put the helping verb (a form of to be) into the past tense and use the -ing form of main verb:

–We are playing tennis.
–>We were playing tennis.

Examples of Past Progressive

• She was talking on the phone when I arrived.
• They were cleaning the house when he called.