This document discusses the difference between using "while" and "when" to link actions in the past. It states that "while" is used to connect two continuous actions that happened simultaneously in the past tense, whereas "when" connects a long ongoing action in the past continuous tense with a short action that occurred in the past simple tense. Examples are provided to illustrate the proper usage of each conjunction.

1. The use of when and while

2. While
• We use while to link two continuous
actions that happened at the same time
in the past.
• We use the past continuous tense for
both actions.

3. while
Tom and Mary were doing their homework.
NOW
5:00 p.m. 7:00 p.m. 8:00 p.m.
Mum was cooking the dinner.
Tom and Mary were doing their homework
while Mum was cooking the dinner.

4. while
Tom was eating.
NOW
5:00 p.m. 7:00 p.m. 8:00 p.m.
Tom was watching TV.
Tom was eating while he was watching TV.

5. When
We use when to link a long action and a
short action.
We use the past continuous tense for the
long action. We use the past tense for
the
short action.

6. when
Tim was doing his homework.
NOW
5:00 p.m. 7:00 p.m. 8:00 p.m.
Mum came home at 6:30 p.m.
Tim was doing his homework
when Mum came home.

7. when
Tim was taking a shower.
NOW
5:00 p.m. 7:00 p.m. 8:00 p.m.
The doorbell rang.
Tim was taking a shower when
the doorbell rang.

8. Two actions were happening at the same time in the past
(draw a picture) (smile)
was drawing a picture while he was smiling.
John __________________________________________

9. A long action was happening and then a short action
happened in the past.
(use the computer) (the computer break down)
was using the computer when the computer
Mr.Lee ______________________________________
broke down.
_______________________

10. A long action was happening and then a short action
happened in the past.
(Grandma fall on the floor) (Mary skip)
fell on the floor when Mary was skipping
Grandma ______________________________________

11. Two actions were happening at the same time in the past
(The man eat)
(The women chat)
were chatting while the man was eating.
The women _____________________________________

12. Note:
e.g. 1. I was cooking dinner when I burnt my arm. 
2. I burnt my arm while I was cooking dinner. 
We can also use ‘while’ in the second sentence, but while
must be followed by past continuous tense.
I was cooking dinner while I burnt my arm 