if條件狀語從句和賓語從句（課堂PPT）

1、1Adverbial Clause of Conditionif 引導(dǎo)的條件狀語從句引導(dǎo)的條件狀語從句& &賓語從句賓語從句-復(fù)習(xí)課復(fù)習(xí)課2She is doing her homework.If you are hard-working, you will get good grades.She gets good grades.3If you play computer games on weekdays ,youll be very tired in classyour parents will be sad.you wont get good grades.your e

2、yes will be poor41) 條件狀語從句通常由if或或unless(=if not)引導(dǎo)，從句中常用一般時代替將來時一般時代替將來時，即if或unless后的句子謂語用一般現(xiàn)在時。但是，主句則通常用將來時，情態(tài)動詞或祈使句。 時態(tài)主將從現(xiàn)時態(tài)主將從現(xiàn)主句一般將來時，主句一般將來時，從句一般現(xiàn)在時從句一般現(xiàn)在時51. 如果主句是一般將來時，從句則用一般現(xiàn)在時。如果主句是一般將來時，從句則用一般現(xiàn)在時。 If it rains（從句），（從句）， I will stay at home. Ill go with you if you dont want to go alone（從句）（

3、從句）. 2.如果主句含有如果主句含有must, may, can 等情態(tài)動詞，從句也要用等情態(tài)動詞，從句也要用一般現(xiàn)在時。一般現(xiàn)在時。 If you drive too fast, you may have an accident. You must stop if the traffic light is red.3. 如果主句是祈使句，從句同樣要用一般現(xiàn)在時。如果主句是祈使句，從句同樣要用一般現(xiàn)在時。 Dont go and play football if you dont finish your homework. Please call me if he comes next Su

4、nday. if條件狀語從句結(jié)構(gòu)及時態(tài)條件狀語從句結(jié)構(gòu)及時態(tài)Revision6 If 引導(dǎo)條狀語從句時，從句中用一般現(xiàn)在時代替一般將來時。1. If he _(go) to the movies,he wont finish his work.goes 2. If I _(become) a doctor,I can help others. become3. If we _(have )time, we will go to the park tomorrow.have4.如果你去，如果你去， 我也去。我也去。If you go,I will go.5.如果明天下雨，請帶雨衣如果明天下雨，請

5、帶雨衣。 raincoatPlease take a raincoat if it rains.7If you are free this weekend,what will you do ?If I am free ,sleepwatch TVplay computer gamespractice8If 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 te

6、achers carefully. do homework by yourself. copy your homework. talk in the class cheat in the exams9If 條件句的替代形式：條件句的替代形式：（1）祈使句祈使句 + and/or + 陳述句陳述句（謂語動詞通常用將來時態(tài)（謂語動詞通常用將來時態(tài)）。其中，）。其中，and表示句意順承；表示句意順承；or表示轉(zhuǎn)折，意為表示轉(zhuǎn)折，意為“否則否則”。e.g. If you work hard, youll pass the exam easily. = Work hard, and youll pass

7、 the exam easily.If you dont work hard, youll fall behind others. = Work hard, or youll fall behind others.10（2）用介詞）用介詞with, without的替代形式：的替代形式： e.g. If there is no 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

8、on time.11If 在賓語從句中翻譯為在賓語從句中翻譯為“是否是否”If 在條件狀語從句中翻譯為在條件狀語從句中翻譯為“如果如果”Ill go to see you if I am free next week. I want to know if he is a teacher.whether1. if 在句中的含義不同在句中的含義不同122. if 在從句中的位置不同在從句中的位置不同If 引導(dǎo)的賓語從句放在主句之后；而引導(dǎo)的賓語從句放在主句之后；而if引引導(dǎo)的狀語從句可放在主句之前也可放在主導(dǎo)的狀語從句可放在主句之前也可放在主句之后句之后= If it doesnt rain, I

9、 will go out tomorrow.I will go out tomorrow if it doesnt rain.I dont know if the train has arrived. If 引導(dǎo)的條件狀語從句放于句首時多用逗號隔開；引導(dǎo)的條件狀語從句放于句首時多用逗號隔開；而而if引導(dǎo)的賓語從句則不能。引導(dǎo)的賓語從句則不能。133. 時態(tài)要求上有區(qū)別時態(tài)要求上有區(qū)別If 引導(dǎo)條件狀語從句的時態(tài)為一般現(xiàn)在時引導(dǎo)條件狀語從句的時態(tài)為一般現(xiàn)在時 記住記住“主將從現(xiàn)主將從現(xiàn)” 1.I want to know if there a sports meeting next month.

10、doesnt rainwill be2.If it doesnt rain ,well go outIf 引導(dǎo)的賓語從句的時態(tài)由主句及本身時引導(dǎo)的賓語從句的時態(tài)由主句及本身時態(tài)決定；態(tài)決定；141. 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 , we will get good results .151 If I _(n

11、ot understand）, I will ask my teacher for help . If I _(copy ) your homework , I will cheat myself . I dont know if it _ (rain) tomorrow.2 My teacher asked me if I _ (finish) my homework already. dont understand copy will rain had finished16if的用法的用法2.引導(dǎo)條件狀語從句：引導(dǎo)條件狀語從句：譯為譯為“如果，假如如果，假如”(1) if從句從句+祈使句祈使句(2) if從句從句+主句（一般將來時）主句（一般將來時）(3) if從句從句+主句（含有情態(tài)動詞）主句（含有情態(tài)動詞） 1.引導(dǎo)賓語從句引導(dǎo)賓語從