Past Continuous tense

Past continuous tense 

The past continuous is a verb tense which is used to show that an ongoing past action was happening at a specific moment of interruption, or that two ongoing actions were happening at the same time. Read on for detailed descriptions, examples, and past continuous exercises.

Past Continuous Forms

The past continuous is formed using was/were + present participle. Questions are indicated by inverting the subject and was/were. Negatives are made with not.

Statement: You were studying when she called.
Question: Were you studying when she called?
Negative: You were not studying when she called.

Here you can see a complete list of past contunuous forms: 
https://www.englishpage.com/verbpage/pastcontinuousforms.html 

USE 1 Interrupted Action in the Past

Use the past continuous to indicate that a longer action in the past was interrupted. The interruption is usually a shorter action in the simple past. Remember this can be a real interruption or just an interruption in time.

Examples:

• I was watching TV when she called.
• When the phone rang, she was writing a letter.
• I was listening to my iPod, so I didn't hear the fire alarm.
• While John was sleeping last night, someone stole his car.
• Sammy was waiting for us when we got off the plane.

USE 2 Specific Time as an Interruption

In USE 1, described above, the past continuous is interrupted by a shorter action in the simple past. However, you can also use a specific time as an interruption.

Examples:

• Last night at 6 PM, I was eating dinner.
• At midnight, we were still driving through the desert.
• Yesterday at this time, I was sitting at my desk at work.

IMPORTANT

In the simple past, a specific time is used to show when an action began or finished. In the past continuous, a specific time only interrupts the action.

Examples:

• Last night at 6 PM, I ate dinner.
• I started eating at 6 PM.

USE 3 Parallel Actions

When you use the past continuous with two actions in the same sentence, it expresses the idea that both actions were happening at the same time. The actions are parallel.

Examples:

• I was studying while he was making dinner.
• While Ellen was reading, Tim was watching television.
• Were you listening while he was talking?
• I wasn't paying attention while I was writing the letter, so I made several mistakes.

Here you can practice everything you've learned before.

https://agendaweb.org/verbs/past_progressive-exercises.html