if条件状语从句和宾语从句.pptVIP

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 , you’ll be very tired in class your parents will be sad. you won’t get good grades. your eyes will be 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. I’ll go with you if you don’t 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, 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。 Don’t go and play football if you don’t 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 won’t finish his work. 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. If you are free this weekend, what will you do ? If I am free ,… sleep watch TV play computer games practice If you want to get good marks,do what? Don’t do what? If you want to get good marks, __________. If you want to get good marks, don’t __________. 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 + 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, you’ll pass the exam easily. = Work hard, and you’ll pass the exam easily. If you don’t work hard, you’ll fall behind others. = Work hard, or you’ll fall behind others. （2）用介词with, without的替代形式： e.g. If there is no water, the fish may die.