if条件状语从句和宾语从句.ppt

1、Revision,Adverbial Clause of Condition if 引导的条件状语从句&宾语从句,-复习课,She is doing her homework.,If you are hard-working, you will get good grades.,She gets good grades.,If you play computer games on weekdays ,youll be very tired in class,your parents will be sad.,you wont get good grades.,your eyes will be

2、 poor,1) 条件状语从句通常由if或unless(=if not)引导，从句中常用一般时代替将来时，即if或unless后的句子谓语用一般现在时。但是，主句则通常用将来时，情态动词或祈使句。,时态主将从现 主句一般将来时， 从句一般现在时,1. 如果主句是一般将来时，从句则用一般现在时。 If it rains（从句）， I will stay at home. Ill go with you if you dont want to go alone（从句）. 2.如果主句含有must, may, can 等情态动词，从句也要用 一般现在时。 If you drive too fast,

3、 you may have an accident. You must stop if the traffic light is red. 3. 如果主句是祈使句，从句同样要用一般现在时。 Dont go and play football if you dont finish your homework. Please call me if he comes next Sunday.,if条件状语从句结构及时态,Revision,If 引导条状语从句时，从句中用一般现在时代替一般将来时。,1. If he _(go) to the movies,he wont finish his work

4、.,goes,2. If I _(become) a doctor,I can help others.,become,3. If we _(have )time, we will go to the park tomorrow.,have,4.如果你去， 我也去。,If you go,I will go.,5.如果明天下雨，请带雨衣。 raincoat,Please take a raincoat if it rains.,excellent,If you are free this weekend, what will you do ?,If I am free ,sleep watch

5、TV play computer games,practice,If you want to get good marks,do what? Dont do what?,If you want to get good marks, _. If you want to get good marks, dont _.,study hard listen to teachers carefully. do homework by yourself.,copy your homework. talk in the class cheat in the exams,If 条件句的替代形式： （1）祈使句

6、 + and/or + 陈述句（谓语动词通常用将来时态）。其中，and表示句意顺承；or表示转折，意为“否则”。 e.g. If you work hard, youll pass the exam easily. = Work hard, and youll pass the exam easily. If you dont work hard, youll fall behind others. = Work hard, or youll fall behind others.,very good,（2）用介词with, without的替代形式： e.g. If there is no

7、water, the fish may die. = Fish may die without water. If you help me, Ill finish my task on time. =With your help, Ill finish my task on time.,if 引导的条件状语从句和if 引导的宾语从句的区分:,If 在宾语从句中翻译为“是否” If 在条件状语从句中翻译为“如果”,Ill go to see you if I am free next week.,I want to know if he is a teacher.,whether,1. if 在

8、句中的含义不同,2. if 在从句中的位置不同,If 引导的宾语从句放在主句之后；而if引导的状语从句可放在主句之前也可放在主句之后,= If it doesnt rain, I will go out tomorrow.,I will go out tomorrow if it doesnt rain.,I dont know if the train has arrived.,If 引导的条件状语从句放于句首时多用逗号隔开；而if引导的宾语从句则不能。,3. 时态要求上有区别,If 引导条件状语从句的时态为一般现在时 记住“主将从现”,1.I want to know if there a

9、 sports meeting next month.,doesnt rain,will be,2.If it doesnt rain ,well go out,If 引导的宾语从句的时态由主句及本身时态决定；,找出下列句子中哪些是if条件状语从句，哪些是if宾语从句,1. Can you tell me if she can come to the meeting ? 2. She will not go there if it is rainy tomorrow. 3. I cant guess if she will be angry . 4. If we help each other

10、 , we will get good results .,If 引导的条件状语从句或宾语从句的练习,1 If I _(not understand）, I will ask my teacher for help . If I _(copy ) your homework , I will cheat myself . I dont know if it _ (rain) tomorrow. My teacher asked me if I _ (finish) my homework already.,dont understand,copy,will rain,had finished,summary,if的用法,2.引导条件状语从句：译为“如果，假如” (1) if从句+祈使句 (2) if从句+主句（一般将来时） (3