Unit 1 Teenagers today单元核心语法精讲与精练-2026-2027 学年外研版九年级上册英语

**基本信息** 聚焦条件与原因状语从句，通过“概念-考点-易混点-拓展”四层逻辑架构，结合表格化方法提炼与多样化题型训练，系统提升语法应用能力与应试思维。 **专项设计** |模块|题量/典例|方法提炼|知识逻辑| |----|-----------|----------|----------| |条件状语从句|4大核心考点（时态规则表）、if词性区分、unless替换|主将从现/主情从现等时态规则，if两种词性辨析技巧|从基础概念（语序/标点）到核心考点（时态），再到易混点（if多义）及拓展（同义替换）| |原因状语从句|引导词对比表（because/since等）|because回答why、since放句首等用法规则，because与because of区分|从基础概念（原因表达）到引导词功能对比（语气/句式），标注必考与拓展层级| |考点精练|单选20/填空15/句型转换10|时态应用、同义转换、引导词选择技巧|覆盖从句时态、结构转换、易混词辨析等中考高频考向，实现知识向能力转化|

答案解析 一、单项选择（共20小题） 1. 答案：D。解析：第一空if意为“是否”引导宾语从句，根据语境将来会发生，用will pass；第二空if意为“如果”引导条件状语从句，遵循主将从现，从句用一般现在时works，故选D。 2. 答案：A。解析：第一空if“是否”引导宾语从句，tomorrow表将来用will come；第二空if“如果”引导条件状语从句，主将从现，从句主语he三单用comes，故选A。 3. 答案：A。解析：as拓展引导原因状语从句，表“因为”；so因此，but但是，than比，均不符合逻辑，句意为因为天气不好我们只能待在家，选A。 4. 答案：B。解析：since引导原因状语从句，意为“既然”；but但是，so因此，though虽然，句意既然他有丰富演讲经验，就让他做发言人，选B。 5. 答案：A。解析：because与so不能同句连用，though与but不能同句连用；本句表下雨是待在家的原因，只用because，后面不加so，选A。 6. 答案：C。解析：问句Why提问原因，答句用because回答缘由；what什么，how怎样，which哪一个均不用于回答why，选C。 7. 答案：A。解析：because后接完整句子he was ill；because of后接名词短语the bad weather，符合规则，选A。 8. 答案：A。解析：本句为if条件状语从句主现从现（客观常识），主语it三单，谓语动词用turns，选A。 9. 答案：D。解析：unless=if…not，意为“除非”；if如果，until直到，because因为，句意除非我们经常使用，否则会遗忘，选D。 10. 答案：C。解析：if条件状语从句主将从现，从句主语you用动词原形study，主句用will pass，选C。 11. 答案：D。解析：主情从现结构，从句主语you搭配are hungry；主句情态动词can后接动词原形buy，选D。 12. 答案：C。解析：if条件状语从句，从句用一般现在时；主语you，动词用原形return，选C。 13. 答案：A。解析：if引导条件状语从句，从句用一般现在时，主语you，动词原形try，选A。 14. 答案：A。解析：主将从现，从句主语they搭配be动词are，选A。 15. 答案：B。解析：主将从现，从句主语it三单，动词rain变rains，选B。 16. 答案：A。解析：主将从现，从句主语it搭配be动词is，选A。 17. 答案：A。解析：主将从现，从句否定形式，主语it，助动词doesn’t+动词原形rain，选A。 18. 答案：A。解析：主将从现，主句用一般将来时will sell，选A。 19. 答案：A。解析：主祈从现结构，if从句后接祈使句，动词原形take开头，选A。 20. 答案：A。解析：主现从现（客观规则），从句主语you，动词原形break，选A。 二、用所给单词的适当形式填空（共15小题） 1. 答案：continues。解析：if条件状语从句主将从现，主语it三单，动词continue变形continues。 2. 答案：doesn’t rain。解析：主将从现，主语it三单，否定形式doesn’t+动词原形rain。 3. 答案：doesn’t rain。解析：同第2题，从句一般现在时否定，it作主语用doesn’t rain。 4. 答案：invites。解析：主将从现，主语the person单数，invite变为三单invites。 5. 答案：tell; need。解析：前半句主祈从现，祈使句用动词原形tell；从句主语you，动词原形need。 6. 答案：refuses。解析：主将从现，主语his friend单数，refuse三单refuses。 7. 答案：fail。解析：主祈从现，从句主语you，动词原形fail。 8. 答案：give。解析：主将从现，从句主语you，动词原形give。 9. 答案：drop。解析：主祈从现，主句为祈使句，动词原形drop开头。 10. 答案：attacks。解析：主现从现（客观常识），主语a dog单数，attack三单attacks。 11. 答案：didn’t know; didn’t look。解析：because引导原因状语从句，动作均发生在过去，统一用一般过去时否定didn’t+动词原形。 12. 答案：will lend; has。解析：主将从现，主句will lend；从句主语she三单，have变has。 13. 答案：donate; cut。解析：主情从现，情态动词can后接动词原形donate；从句主语we，动词原形cut。 14. 答案：aren’t。解析：主将从现，主语you，be动词否定形式aren’t。 15. 答案：overslept。解析：because引导原因状语从句，this morning为过去时间，用一般过去时overslept。 三、句型转换（共10小题） 1. 答案：because of。解析：because后接完整句子，because of后接名词短语the heavy snow，属于拓展知识点。 2. 答案：He couldn’t go to the party because he had a lot of work to do.。解析：because与so不能同句连用，去掉so，because引导原因从句放主句后，时态保持一般过去时。 3. 答案：If you don’t help me, I can’t finish the task.。解析：unless = if…not，if从句放句首，末尾加逗号，其余内容不变。 4. 答案：If you visit the park, you will have a lot of fun.。解析：if条件从句前置，句尾加逗号，主句语序、时态不变。 5. 答案：If you play。解析：“祈使句+or+简单句”转换为主将从现，if从句放句首，主语you搭配动词原形play。 6. 答案：If you work hard。解析：“祈使句and陈述句”转换为if条件状语从句，从句If you work hard，遵循主将从现。 7. 答案：don’t; will be。解析：“祈使句or简单句”转换为if…not结构，从句一般现在时don’t get up；主句将来时will be late。 8. 答案：Since you don’t feel very well, you had better stay at home.。解析：since引导原因状语从句，引出双方已知的原因，从句放句首加逗号。 9. 答案：If it doesn’t rain, we will go for a picnic.。解析：无雨转化为if条件从句it doesn’t rain，遵循主将从现规则。 10. 答案：If you don’t。解析：“祈使句or陈述句”转换为if否定条件句，三空依次填If you don’t，后接动词原形protect。 学科网（北京）股份有限公司 $夯实语法根基・突破时态难点・单元专项精练 外研版（2024）九年级上册Unit 1 Teenagers today 单元核心语法精讲精练 核心语法：条件状语从句 & 原因状语从句 知识点1 if引导的条件状语从句 1. 基础概念 (1) if意为“如果”，引导条件状语，描述满足某条件后会发生的结果，从句表将来时统一用一般现在时。 (2) 语序标点规则： ① If从句放句首，从句末尾加逗号； ② If从句放句尾，无需逗号。 示例：If it rains, we will stay at home. = We will stay at home if it rains. 2. 四大核心考点（必考） 时态规则 主句结构 从句时态 例句 主将从现 一般将来时（will + 动词原形） 一般现在时 If it rains tomorrow, we will stay at home. 主情从现 情态动词can/may/must/should + 动词原形 一般现在时 If you want to see more, you can look at the guide. 主祈从现 祈使句（动词原形开头） 一般现在时 If you do not feel well, please go to see the doctor. 主现从现 客观真理、常识（ 一般现在时） 一般现在时 If you heat ice, it melts. 3. 易混点：if两种词性区分（考试重难点） (1) 条件状语从句 if=如果 从句禁止使用will，只用一般现在时 例句：If he comes tomorrow, please tell me. (2) 宾语从句 if=是否 从句可根据时间使用will，跟know/wonder等动词后 例句：I don’t know if he will come tomorrow. 4. 拓展同义替换 unless = if…not 例句：Unless you hurry up, you will be late. = If you don’t hurry up, you will be late. 知识点2 because、since引导的原因状语从句 1. 基础概念 because、since用来引出主句发生的原因，because与so不可同句连用。 区分： ① since（连词）既然，表原因； ② since（介词）自从，接时间。 2. 引导词用法对比（标注必考/拓展） 引导词/短语 核心用法 句式要求 例句 层级标注 because 语气最强，专门回答why提问 后接完整句子，主句前后均可 Mark couldn’t come because he had to work. 单元必考 since 语气中等，引出双方都知道的已知原因，常放句首 后接完整句子 Since everyone is here, let’s start. 单元必考 because of 表原因的介词短语 后接名词/代词/动名词，不能接完整句子 He failed because of carelessness. 拓展知识点 as 语气最弱，仅铺垫背景信息 后接完整句子，多放句首 As it was late, we went home. 拓展知识点 考点精练 一、单项选择（共20小题） 从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。 ( )1．I’m not sure if he ______ the exam. But he will be better if he _____ harder. A．passes; will work B．passes; works C．will pass; will work D．will pass; works ( )2．I don’t know if he _______ tomorrow. If he _________, please let me know. A．will come; comes B．will come; will come C．comes; comes D．comes; will come ( )3．We have to stay at home ________ the weather is bad. A．as B．so C．but D．than ( )4．________ he has a lot of public speaking experience, he will be our speaker. A．But B．Since C．So D．Though ( )5．________ it rained hard, ________ I stayed at home. A．Because; / B．Because; so C．Though; but D．Though; / ( )6．—________ do you like Chinese New Year? —________ I can get a lot of red packets. A．What; So B．How; But C．Why; Because D．Which; And ( )7．He didn’t go to school ________ he was ill. And his sister also stayed at home ________ the bad weather. A．because; because of B．because of; because C．because; because D．because of; because of ( )8．The temperature in North China is often below 0°C in winter. If you put water outside, it ________ into ice. A．turn B．will turn C．would turn D．is turning ( )9．Even if we learn something well, we will forget it ________ we often use it. A．if B．until C．because D．unless ( )10．If you ________ hard, you ________ the exam easily. A．study; pass B．will study; will pass C．study; will pass D．will study; pass ( )11．If you ________, you ________ some snacks. A．will be hungry; bought B．are hungry; bought C．be hungry; will buy D．are hungry; can buy ( )12．If you ________ to Beijing from other countries, you must stay at home for at least 14 days. A．returned B．returns C．return D．will return ( )13．—I nearly give up. All methods didn’t work. —Well, you may get a surprise if you ________ to think outside the box. A．try B．tried C．will try D．are trying ( )14．My parents will go for an outing if they ________ free next Sunday. A．are B．will be C．have D．will have ( )15．If it ________ tomorrow, we won’t have a picnic. A．rain B．rains C．rained D．will rain ( )16．—Will you go to the park if it ________ fine? —Yes, I will. A．is B．will be C．be D．was ( )17．—I’ll go for a picnic if it __________ tomorrow. Will you go with me? —Yes, of course. A．doesn’t rain B．isn’t raining C．won’t rain D．didn’t rain ( )18．—If I have a chance to help farmers, I ________ their products online. —That sounds great! A．will sell B．am selling C．sold D．was selling ( )19．If you feel tired, ________ a short rest right now. A．take B．will take C．takes D．taking ( )20．You should apologize if you ________ a rule by accident. A．break B．breaking C．to break D．broke 二、用所给单词的适当形式填空（共15小题） 1．If it ________ (continue) to rain, we may have to cancel the outdoor party. 2．If it ________ (not rain) tomorrow, we will go walking in the park. 3．We’ll go to the park if it __________ (not rain) tomorrow. 4．You can use the first name if the person ________ (invite) you to. 5．Please ________ (tell) me if you ________ (need) help with your budget. 6．What will happen if his friend ________ (refuse) the invitation next month. 7．Don’t worry if you ________ (fail) once. Try again. 8．If you ________ (give) a cat some milk, she will become your friend. 9．If you think you can come, ________ (drop) me a line. 10．Remember to stay calm if a dog ________ you. (attack) 11．I ________(not know) the car was expensive because I ________ (not look) at the price. 12．She ________ (lend) you some coins if she ________ (have) extra. 13．We can ________ (donate) money if we ________ (cut) useless spending. 14．If you ________ (not be) free this Saturday, I will ask someone else for help. 15．I ________ this morning because my neighbor invited his friends to have a party at night and they were too noisy. (oversleep) 三、句型转换（共10小题） 按要求完成下列句子，每空一词。 1．I can't get to school on time because it snows heavily. (改为同义句) I can't get to school on time ________ ________ the heavy snow. 2．He had a lot of work to do, so he couldn’t go to the party. （改为同义句，用because） ________________________________ 3．Unless you help me, I can’t finish the task.（改为同义句，用if…not） ________________________________ 4．You will have a lot of fun if you visit the park.（改为从句在前） __________________________________________________________ 5．Don’t play on the street, or you will be in danger. (同义句转换) ________ ________ ________ on the street, you will be in danger. 6．Work hard and you will make great progress. ________ ________ ________ ________, you will make great progress. 7．Get up early, or you will be late. If you ________ get up early, you ________ ________ late. 8．You had better stay at home. You don't feel very well．（改为同义句，用 since连接） _______________________________________________________________ 9．No rain, and we will go for a picnic. (改为同义句，用if) _______________________________________________________________ 10．Protect your skin from the sun or your skin will get hurt. (改为同义句) ________ ________ _______ protect your skin from the sun, your skin will get hurt. 学科网（北京）股份有限公司 $