Unit 7语法（条件状语从句）培优讲义2025-2026学年沪教版（2024）八年级英语上册

八上Unit 7语法（条件状语从句）培优讲义 一、定义​ 条件状语从句是由一个条件引导词（如 if_____________，unless_____________，as long as____________ 等）引导的从句，用来表达某种条件下发生的情况。引导词部分是从句，其余是主句。 二、条件状语从句的位置​ 条件状语从句可位于句首，也可位于句末。放在句首时，从句后通常用逗号与主句隔开。放在句末时，从句与主句之间一般不用逗号。​ If it doesn't rain tomorrow, I'll bring you to the park.（如果明天不下雨，我将带你去公园。）​ He will go to play the game unless he is ill tomorrow.（除非他明天病了，不然他会参加这场比赛。）​ 三、条件状语从句的时态​ （一）主将从现​ 当主句的谓语动词是一般将来时，条件状语从句用一般现在时。 I _______________ _______________ _______________ _______________if _______________ _______________ tomorrow.（如果明天下雨，我就呆在家里。）​ If you_______________ _______________my party, I _______________ _______________ very happy.（如果你来参加我的派对，我会非常开心。）​ （二）主情从现​ 当主句的谓语含有 can，may，must 等情态动词时，条件状语从句用一般现在时。​ You may watch TV if you _______________ _______________ _______________.（如果你完成了作业你可以看电视。）​ We can go for a picnic if _______________ _______________ _______________ _______________.（如果天气好，我们可以去野餐。）​ （三）主祈从现​ 当主句是祈使句时，条件状语从句用一般现在时。​ _______________ _______________ unless you finish your work.（不要玩，除非你把活做完了。）​ Please _______________ _______________ if you get home.（如果你到家了，请给我打电话。）​ 四、unless，if....not ，as long as用法​ unless引导的条件状语从句表示 “除非…… 否则……” 的关系。​ I _______________ _______________ _______________ unless _______________ _______________ _______________.（除非雨停了，否则我不会出去。） You _______________ _______________ _______________ unless you _______________ _______________ _______________.（除非你完成作业，否则你不能看电视。）​ if...not 也表达否定条件，表示 “……如果不， 就不能……” 的关系。 You _______________ _______________ _______________ if you _______________ _______________ _______________.（如果你不完成作业，你不能看电视。）​ as long as 引导的条件状语从句表示 “只要…… 就……” 的关系。​ You_______________ _______________ _______________ to play as long as you_______________ _______________ _______________.（只要你完成作业，你就可以出去玩。）​ I _______________ _______________ _______________you as long as _______________ _______________ _______________.（只要你努力工作，我会支持你。）​ 五、练习​ （一）单项选择​ 1.I will call you if he ______ back.​ A. come B. comes C. will come D. came​ 2.You will be late for school ______ you don't get up early.​ A. but B. and C. if D. or​ 3.We ______ shopping unless it ______ tomorrow.​ A. will go; will rain B. go; will rain C. will go; rains D. go; rains​ 4.You can't pass the exam ______ you study hard.​ A. if B. unless C. or D. so​ 5.As long as you ______ hard, you will get good grades.​ A. will study B. studied C. study D. studies​ （二）用所给词的适当形式填空​ 1.If he ______ (come) tomorrow, I will tell him the news.​ 2.You won't pass the test unless you ______ (work) hard.​ 3.We can go to the park if it ______ (not rain) tomorrow.​ 4.As long as you keep ______ (practice), you will improve your English.​ 5.I will go to the party if he ______ (invite) me.​ （三）翻译句子​ 如果你努力学习，你将会取得进步。​ _________________________________________________________________________________________ _________________________________________________________________________________________ 除非你早点起床，否则你会错过早班车。​ _________________________________________________________________________________________ _________________________________________________________________________________________ 只要你遵守规则，你就可以在这里玩。​ _________________________________________________________________________________________ _________________________________________________________________________________________ 如果明天天气好，我们就去钓鱼。​ _________________________________________________________________________________________ _________________________________________________________________________________________ 如果他有空，他会和我们一起去看电影。​ _________________________________________________________________________________________ _________________________________________________________________________________________ 答案​ （一）单项选择​ 1.B 2.C 3.C 4.B 5.C （二）用所给词的适当形式填空​ 1.comes 2. work 3. doesn't rain 4.practicing 5.invites （三）翻译句子​ 1.If you study hard, you will make progress.​ 2.You will miss the early bus unless you get up early.​ 3.As long as you follow the rules, you can play here.​ 4.If the weather is fine tomorrow, we will go fishing.​ 5.If he is free, he will go to the movies with us. 学科网（北京）股份有限公司 $$