Unit 5 What were you doing when the rainstorm came?when和while引导的时间状语从句的区别（课件）（共有PPT8张)

(共8张PPT)
课题：Unit 5What were you doingwhen the rainstorm came 难点名称：正确理解when和while引导的时间状语从句的区别八年级-下册-unit5导入状语-谓语动词的状态，包括时间，地点，原因，方式，目的，结果，让步，比较等。She studies hard in the university every day.在本句中hard就是方式状语，in the university就是地点状语，而every day是时间状语She studied hard when she was three years old.在本句中she was three years old 是由when引导的时间状语从句在本节课中我们将学习when和while引导的时间状语从句有什么区别。when的用法：
1.I was just reading a book when she came into my room.
2.Were you writing when the teacher came in
3.When he was a child,he was always trying out new ideas.
通过观察例句我们发现when在引导时间状语从句，when后面的动词可以是时间点，也可以是时间段，when后的动作可以跟延续性动词和非延续性动词。
while的用法
1.While Jim was mending his bike，Li Ming rang him.
2.You can’t do your homework while you are watching TV.
3.Tom was cleaning the room while Jim was doing homework.
通过观察例句我们发现while在引导时间状语从句时，表达某一时间段范围内的动作，因此while后面的动作只跟延续性动词。
在选择用when还是while的时候我们可以通过两种方式来判断
第一种：看动词：从句中的动词为短暂性动词（come，go，leave.die.open.borrow等），只用when不用while；
第二种：看时态：强调主句动作和从句动作同时发生；主从句的时态都为进行时的时候；只能用while。
1.-I phoned you this afternoon，but no one answered.
-I was helping Tom with his Chinese at his home you phoned me.
根据句意你给我打电话的时候我正在帮助汤姆补习中文，从句中phoned为非延续性动词，因此，此处只能填when；
2. I was doing the washing in the house. my brother was playing with his pet dog in the garden.
根据句意我正在家里洗碗，而我的弟弟正在花园里和狗一起玩。前后两件事是同时发生的，主句和从句的动词do和play都是延续性动词，主从句都是过去进行时，因此此处只能用while
同学们，学会了吗？练习挑战一下吧。
小结
谢谢聆听！