[中学联盟]江苏省东海县晶都双语学校九年级英语上册教学课件：9A Unit 4 Grammar 1.ppt

(Ⅰ) Unit 4 To learn to use the following conjunctions to introduce time clauses: using before, after, when and while Learning aims:(1) after before at an earlier time than at a later time than Know about the meaning and usage of before and after Guide one(10) now Before Lin could walk, he played with the ball all day long. After Lin could run, he played with the basketball with his father. Before he went to school, he was interested in playing basketball. After he went to school, …. Do you know Lin Shuhao?Lets learn about him. 1.He played basketball for hours every day. He felt very tired. 2.He tried out for the school team. He practised a lot with his teammates. 3.He graduated from Harvard. He decided to play basketball as his career. After he played basketball for hours every day, he felt tired. Before he tried out for the school team, he practised a lot with teammates. After he graduated from Harvard, he decided to play basketball as his career. After he practised a lot with teammates, he tried out for the school team. Put the sentences together with before or after Practice: before的意思是“在……之前” Close the windows before you leave the room, please. 在你离开房间前，请关上窗。 after意思是“在……之后”， I went to school after I finished my breakfast. 我吃完早饭去上学。 Summary Guide Two(15) Learn about the meaning and usage of whenand while when意思是“当……时”，表示主句动作发生的特定时间。如： While my sister was sweeping the floor, I was washing the dishes. 我姐姐扫地时，我在洗碗。 while意思是“当……时”，强调主句动作和从句动作是同时发生的。如： The days get longer when spring comes. 春天到来时，白天变长了。 注意：while引导的从句的谓语动词必须是延续性的。 注意： 在when和while引导的从句中，当主句和从句的主语一致，并且从句中有be动词时，可以省略主语和be动词，构成when/while+ -ing结构。如： When (she is) in trouble, she always asks for my help. 她遇到困难时总是向我求助。 While (I am) travelling, I like to buy some souvenirs. 旅游时我喜欢买纪念品。 while还可以表示“在……期间”，表示主句动作发生在从句动作进行的过程中。如: While the boys were playing football, it rained.当男孩子们踢足球时，下雨了。 while表示“而，却”，表对照关系。 He is strong while his brother is weak.