1 It is used to describe an action in progress in the Past.
2 The main verb is always conjugated in the Participle form.
3 To indicate that the action was in progress, we write the Verb with "-ing".
4 Stella _____ an apple.
5 Marco and Stella _____ Science.
6 We use the Past Form of the Verb To Be in this tense.
7 She _____ playing hockey.
8 We have to take into account the Irregular form of the main Verb.
9 Tommy was _____ TV last night.
10 My brothers were _____ together.
11 The auxiliary "Did" is used in this tense.
12 Kate _____ good.
13 They _____ there.
14 She _____ a bath when the phone rang.
15 When the car appeared, I _____ Carol.
16 _____ when it started raining?
17 We _____ when the teacher arrived.
18 Which of the sentences is grammatically correct?
19 _____ the truth?
20 I _____ when my boss came in.