Exercise 1: Complete the sentences, using the past continuous of the suitable verbs in the box 
above
1. At this time last year, they (build) _____ this house.
2. I (drive) _____ my car very fast when you called me.
3. I (chat) _____ with my friends while my teacher (teach) _____ the lesson yesterday.
4. My father (watch) _____ TV when I got home.
5. At this time yesterday, I (prepare) _____ for my son’s birthday party.
6. What you (do) _____ at 8 pm yesterday?
7. Where you (go) _____ when I saw you last weekend?
8. They (not go) _____ to school when I met them yesterday.
9. My mother (not do) _____ the housework when my father came home.
10. My sister (read) _____ books while my brother (play) _____ football yesterday afternoon.
Exercise 2: Complete the sentences with past continuous or past simple tense.
1. Yesterday/ when/ he/ carry/ a suitcase/ he/ drop/ it/ on his foot.
...................................................................................................................
2. He/ break/ his leg/ when/ he/ ski/ last month.
...................................................................................................................
3. He/ sit down/ on/ chair/ when/ I/ paint/it.
...................................................................................................................
4. Lan/ sit/ in the garden/ when/ a wasp/ sting/ her/ on the nose
...................................................................................................................
5. As/ we/ drive / down the hill, a strange object/ appear/ in the sky.
..................................................................................................................

Exercise 1: 
1. At this time last year, they (build) were building this house.
2. I (drive) was driving my car very fast when you called me.
3. I (chat) was chatting with my friends while my teacher (teach) was teaching the lesson yesterday.
4. My father (watch) was watching TV when I got home.
5. At this time yesterday, I (prepare) was preparing for my son’s birthday party.

6. What you (do) was you doing at 8 pm yesterday?

7. Where you (go) was you going when I saw you last weekend?

8. They (not go) weren't going to school when I met them yesterday.
9. My mother (not do) wasn't doing the housework when my father came home.
10. My sister (read) was reading books while my brother (play) was playing football yesterday afternoon.

Exercise 2:

1, yesterday / when / he / carry / a suitcase / he / drop / it / on his foot 

=> Yesterday when he carried a suitcase he was dropping it on his foot.

2, he / break / his / leg / when / he / ski / last month

=> He was breaking his leg when he skied last month.

3, he / sit dowm / on / chair / when / i / paint / it

=> He was sitting down on chair when I painted it.

4, Lan / sit / in the garden / when / awasp / sting / her / on the nose

=> Lan was sitting in the garden when a wasp stung her on the nose.

5, as / we / drive / down the hill, a strangge object / appear / in the sky

=> As we were driving down the hill, a strange object appeared in the sky.

lời giải chi tiết

Dấu hiệu nhận biết

• At 9 o’clock yesterday morning: lúc 9h sáng hôm qua
• Last Thursday/ last week/ last …..
• yesterday
• from 3 to 5 o’clock yesterday afternoon
• At this time yesterday

• While: trong khi
• When: khi
• In + năm
• In the past : trong quá khứ

Công thức

• (+) Khẳng định
  S + was/were + V_ing
  Trong đó:
  S = I/He/She/It -> was
  Ex: I was playing football.
  S = You/We/They -> were
  Ex: They were playing football.
• (-) Phủ định
  S + was/were + not + V_ing
  Was not = wasn't, were not = weren't
  Ex: She wasn’t doing exercise at 6 o’clock yesterday. (6h sáng hôm quá, cô ta đang tập thể dục)
• (?) Nghi vấn
  Was/were + S + V_ing?
  Ex: Were you studying English at this time yesterday? (Có phải bạn đang học tiếng Anh vào thời điểm này ngày hôm qua không?)
  → Yes, I was / No, I wasn’t