连词用法全解-高三英语语法专项：十大词性全解

高三英语语法专项：连词用法全解（原卷版） 考点总目录 1. 连词的定义及核心特征 2. 连词的分类及基本用法（并列连词、从属连词，高三核心） 3. 高频并列连词辨析（高考易错） 4. 高频从属连词辨析（高考重难点） 5. 连词的固定搭配及特殊用法 6. 连词过关检测 一、连词的定义及核心特征 核心定义 连词（Conjunction）是用来连接词、短语、句子或从句的词，起衔接、过渡、逻辑连接的作用，无需修饰任何成分，仅负责体现前后内容的逻辑关系（如并列、转折、因果、条件等）。它是高考语法填空、短文改错、完形填空的高频考点，尤其在复合句和并列句中不可或缺，直接影响句子逻辑的连贯性和正确性。 核心特征 1. 功能定位：仅起连接作用，自身无词义（或有轻微逻辑词义），不能作句子成分（主语、谓语、宾语等），也无词形变化（无单复数、时态、人称变化）。 2. 连接对象：可连接两个词（如 A and B）、两个短语（如 go to school and play basketball）、两个句子（如 I like coffee, but she likes tea）、两个从句（如 I know that he is honest and that he works hard）。 3. 逻辑导向：每类连词都有固定的逻辑含义，如“and”表并列，“but”表转折，“because”表因果，需根据句意选择对应连词。 4. 使用禁忌：并列连词不能连接两个独立分句（除非用逗号隔开）；从属连词必须引导从句，不能单独连接两个独立句子。 特征口诀 连词无义只连接，词短语句皆可接； 无变无成分，逻辑是核心； 并列转折表并列，从属引导从句列； 固定搭配记牢固，高考做题不迷路。 单句填空限时训练 1 1. I like reading ______ writing in my free time. 2. She is tired, ______ she still keeps working. 3. He didn’t go to school ______ he was ill. 4. You will pass the exam ______ you study hard. 5. I don’t know ______ he will come or not. 6. She can speak English ______ Chinese fluently. 7. ______ it rains tomorrow, we will stay at home. 8. He is tall ______ strong. 9. I finished my homework ______ my sister watched TV. 10. She asked me ______ I could help her with her English. 11. He is not only a teacher ______ also a writer. 12. I will go to the park ______ the weather is fine. 13. She failed the exam ______ she didn’t study hard. 14. ______ you are right, I still don’t agree with you. 15. I don’t like coffee, ______ I like tea. 16. He told me ______ he would come back soon. 17. You can choose either this book ______ that one. 18. She was late ______ the traffic was heavy. 19. I will call you ______ I arrive in Beijing. 20. ______ he is young, he knows a lot. 二、连词的分类及基本用法（并列连词、从属连词） 连词按功能可分为两大类：并列连词和从属连词，两者核心区别在于：并列连词连接“地位平等”的成分（词、短语、独立句子），从属连词连接“地位不平等”的成分（主句和从句，从句依附于主句）。 1. 并列连词（连接并列成分，无主从之分） 核心功能：连接两个或多个并列的词、短语、独立句子，体现并列、转折、选择、因果等逻辑关系，连接独立句子时，需在连词前加逗号。 常见类型及用法： 1. 表并列关系（and, both...and..., not only...but also...） ✅ 例句：She likes singing and dancing.（连接两个短语）；Both you and I are students.（连接两个人称代词）；He not only studies hard but also helps others.（连接两个谓语） 2. 表转折关系（but, yet, however） ✅ 例句：I tried my best, but I failed.（连接两个独立句子）；He is young, yet he is experienced.（yet 语气比 but 弱）；It was raining, however, we went out.（however 可置于句中、句首或句尾，需用逗号隔开） 3. 表选择关系（or, either...or..., neither...nor...） ✅ 例句：Do you like coffee or tea?（连接两个名词）；Either you leave, or I call the teacher.（连接两个句子）；Neither he nor I know the answer.（连接两个人称代词，主谓一致遵循“就近原则”） 4. 表因果关系（so, for） ✅ 例句：He was ill, so he didn’t go to school.（so 表“所以”，前因后果）；He must be ill, for he is absent today.（for 表“因为”，补充说明原因，不能置于句首） 2. 从属连词（引导从句，有主从之分） 核心功能：引导一个从句（宾语从句、状语从句、定语从句等），依附于主句，体现主句和从句之间的逻辑关系（时间、条件、因果、让步等），从句不能单独成句。 高考高频类型及用法（重点掌握状语从句和宾语从句引导词）： 1. 引导时间状语从句（when, while, as, before, after, until, since） ✅ 例句：When I arrived, he was reading.（when 可接短暂性动词或持续性动词）；While he was reading, I was writing.（while 接持续性动词，表动作同时进行）；I will call you after I finish my work.（after 表“在……之后”） 2. 引导条件状语从句（if, unless, as long as） ✅ 例句：If it rains, we will cancel the trip.（if 表“如果”）；Unless you study hard, you won’t pass the exam.（unless 表“除非”，相当于 if not）；You can succeed as long as you keep trying.（as long as 表“只要”） 3. 引导因果状语从句（because, since, as） ✅ 例句：I didn’t go out because it was raining.（because 表“因为”，回答 why 提问，可置于句首或句末）；Since you are tired, you can have a rest.（since 表“既然”，语气较弱，置于句首）；As it was late, we went home.（as 表“因为”，语气比 since 更弱） 4. 引导让步状语从句（although, though, even if, even though） ✅ 例句：Although he is poor, he is happy.（although/though 表“虽然”，不能与 but 连用）；Even if it snows, we will go to school.（even if 表“即使”，假设一种情况） 5. 引导宾语从句（that, if, whether, what, who, where 等） ✅ 例句：I know that he is a student.（that 引导陈述句宾语从句，可省略）；I wonder if/whether he will come.（if/whether 引导一般疑问句宾语从句，表“是否”）；She asked me where I went yesterday.（where 引导特殊疑问句宾语从句） 单句填空限时训练 2 1. ______ he is rich, he is not happy. 2. I will wait for you ______ you come back. 3. She can ______ sing ______ dance well. 4. He didn’t come to school, ______ he was ill. 5. I don’t know ______ he is at home or not. 6. ______ you work hard, you will get good grades. 7. He likes playing football, ______ his brother likes playing basketball. 8. I have finished my homework, ______ I can watch TV now. 9. ______ I was walking on the street, I saw an old friend. 10. She asked me ______ I had seen her keys. 11. Neither my father ______ my mother likes coffee. 12. ______ it was cold, we still went out for a walk. 13. I will call you ______ I get there. 14. He is not only tall ______ also handsome. 15. You can’t pass the exam ______ you study hard. 16. I know ______ he will come to the party. 17. Either you finish it now ______ you do it tomorrow. 18. ______ he is young, he can speak three languages. 19. I didn’t go to bed ______ I finished my homework. 20. He was late, ______ the traffic was heavy. 三、高频并列连词辨析（高考易错） 高考中并列连词的易错点主要集中在“转折、选择、因果”类连词的辨析，需重点区分含义和用法差异，避免混淆。 1. 易混组1：but vs yet vs however - but：最常用，表强烈转折，连接两个并列分句，可置于分句之间，前面加逗号，后面不加逗号。 ✅ 例句：He is rich, but he is not kind. - yet：语气比 but 弱，表“然而、却”，可置于分句之间（前面加逗号），也可置于句末。 ✅ 例句：She tried hard, yet she failed.；He hasn’t come yet. - however：表“然而”，语气比 but 强，可置于句首（后面加逗号）、句中（前后加逗号）、句末（前面加逗号），不能直接连接两个分句。 ✅ 例句：However, he didn’t give up.；He tried hard, however, he failed. 2. 易混组2：so vs for - so：表“所以、因此”，前因后果，连接两个有因果关系的分句，前面加逗号，可置于分句之间。 ✅ 例句：It was raining, so we stayed at home.（下雨是原因，待在家里是结果） - for：表“因为”，补充说明原因，不能置于句首，前面加逗号，语气比 because 弱，不回答 why 提问。 ✅ 例句：We stayed at home, for it was raining.（补充说明待在家里的原因，不是直接回答 why） 3. 易混组3：either...or... vs neither...nor... vs both...and... - either...or...：表“要么……要么……”，选择关系，两者选其一，主谓一致遵循“就近原则”。 ✅ 例句：Either you or I am wrong.（谓语动词与 I 一致，用 am） - neither...nor...：表“既不……也不……”，否定选择关系，两者都不，主谓一致遵循“就近原则”。 ✅ 例句：Neither he nor his sister likes playing football.（谓语动词与 his sister 一致，用 likes） - both...and...：表“既……又……”，并列关系，两者都，主谓一致用复数。 ✅ 例句：Both my brother and I are students.（谓语动词用 are） 4. 易混组4：and vs or（并列 vs 选择） - and：表“和、并且”，并列关系，连接两个肯定的并列成分。 ✅ 例句：I like apples and bananas. - or：表“或者”，选择关系，连接两个可供选择的成分；在否定句中，or 代替 and，表“和”。 ✅ 例句：Do you like coffee or tea?（选择）；I don’t like apples or bananas.（否定句中表“和”） 单句填空限时训练 3 1. I tried my best, ______ I still failed.（but/yet/however） 2. It was raining, ______ we stayed at home.（so/for） 3. We stayed at home, ______ it was raining.（so/for） 4. ______ he is young, he is very experienced.（but/however/although） 5. Either you ______ your brother must go there.（and/or） 6. Neither you nor I ______ wrong.（am/is/are） 7. Both you and he ______ good at English.（am/is/are） 8. I don’t like coffee ______ tea.（and/or） 9. He is rich, ______ he is not happy.（but/yet/however） 10. She hasn’t finished her homework ______.（but/yet/however） 11. ______, we still have a lot of work to do.（But/Yet/However） 12. He likes playing football, ______ his brother likes playing ping-pong.（but/for） 13. Either you finish it now ______ you do it tomorrow.（and/or） 14. Neither my mother nor my father ______ watching TV.（like/likes） 15. I like singing ______ dancing.（and/or） 四、高频从属连词辨析（高考重难点） 从属连词是高三英语语法的核心重难点，尤其是时间、条件、让步、因果类从属连词，高考中常结合复合句考查，需重点区分含义、用法及易错点。 1. 易混组1：when vs while vs as（时间状语从句） - when：最常用，可引导短暂性动词（如 arrive, leave）或持续性动词（如 read, work），表“当……时”，动作可先后发生或同时发生。 ✅ 例句：When he arrived, we were having dinner.（短暂性动词，先后发生）；When we were reading, he came in.（持续性动词，同时发生） - while：只能引导持续性动词，表“在……期间”，强调两个动作同时进行；也可表对比，意为“而、然而”。 ✅ 例句：While she was cooking, I was cleaning the room.（同时进行）；He likes playing football, while his brother likes playing basketball.（对比） - as：表“当……时”，强调两个动作同时进行，语气比 while 弱，也可表“随着”。 ✅ 例句：As I was walking, I saw a dog.（同时进行）；As time goes by, we grow up.（随着） 2. 易混组2：if vs unless vs as long as（条件状语从句） - if：表“如果”，引导肯定条件，主句用一般将来时，从句用一般现在时（主将从现）。 ✅ 例句：If it rains tomorrow, we will not go out. - unless：表“除非”，相当于“if not”，引导否定条件，主句用一般将来时，从句用一般现在时。 ✅ 例句：Unless you study hard, you won’t pass the exam.（= If you don’t study hard, you won’t pass the exam.） - as long as：表“只要”，引导条件，语气比 if 强，强调“只要满足某个条件，就会产生某个结果”。 ✅ 例句：As long as you keep trying, you will succeed. 3. 易混组3：because vs since vs as（因果状语从句） - because：表“因为”，语气最强，直接说明原因，可置于句首或句末，能回答 why 提问。 ✅ 例句：Why didn’t you go? Because I was ill. - since：表“既然”，语气较弱，引导的原因是已知的、显而易见的，置于句首。 ✅ 例句：Since you are free, you can help me with my homework. - as：表“因为”，语气最弱，引导的原因是补充说明的，可置于句首或句中，不如 because 和 since 强调原因。 ✅ 例句：As it was getting dark, we decided to go home. 4. 易混组4：although/though vs even if/even though（让步状语从句） - although/though：表“虽然、尽管”，两者用法基本一致，though 可置于句末，although 不能；均不能与 but 连用。 ✅ 例句：Although/Though he is short, he is very strong.；He is short, though he is very strong. - even if/even though：表“即使、纵然”，语气比 although/though 强，引导的是假设的、不太可能发生的情况。 ✅ 例句：Even if it snows heavily, we will go to school.（假设下雪的情况，不一定会发生） 5. 易混组5：that vs if/whether（宾语从句） - that：引导陈述句宾语从句，句意完整、不缺成分，that 可省略（填空时需根据语境判断是否需要填写）。 ✅ 例句：I think (that) he is right. - if/whether：引导一般疑问句宾语从句，表“是否”，两者可互换，但以下情况只能用 whether：① 与 or not 连用；② 置于句首；③ 作介词宾语。 ✅ 例句：I wonder if/whether he will come.；I don’t know whether he will come or not.（只能用 whether） 单句填空限时训练 4 1. ______ I was reading a book, my brother was watching TV.（when/while/as） 2. ______ he arrived at the station, the train had left.（when/while/as） 3. ______ time goes by, our friendship becomes stronger.（when/while/as） 4. You will succeed ______ you keep trying.（if/unless/as long as） 5. ______ you don’t study hard, you won’t pass the exam.（if/unless/as long as） 6. ______ it rains, we will cancel the trip.（if/unless/as long as） 7. ______ you are tired, you can have a rest.（because/since/as） 8. I didn’t go out ______ it was raining.（because/since/as） 9. ______ it was late, we went on working.（because/since/as） 10. ______ he is poor, he is very kind.（although/even if） 11. ______ it snows, we will go to school.（although/even if） 12. I know ______ he will come to the party.（that/if/whether） 13. I wonder ______ he will come or not.（that/if/whether） 14. ______ he will come is not sure.（that/if/whether） 15. He likes playing football, ______ his brother likes playing basketball.（when/while/as） 五、连词的固定搭配及特殊用法 1. 常见固定搭配（高考高频） - 并列连词固定搭配： - both...and... 既……又…… → Both she and I are good at English. - not only...but also... 不仅……而且…… → He not only reads books but also writes articles. - either...or... 要么……要么…… → Either you come, or I go. - neither...nor... 既不……也不…… → Neither he nor she likes swimming. - not...but... 不是……而是…… → He is not a teacher but a doctor. - 从属连词固定搭配： - as soon as 一……就…… → As soon as I get home, I will call you. - so...that... 如此……以至于…… → She is so kind that everyone likes her. - such...that... 如此……以至于…… → It is such a beautiful day that we go for a walk. - not...until... 直到……才…… → I didn’t go to bed until I finished my homework. - as if/as though 好像、似乎 → He looks as if he is tired. 2. 特殊用法及易错点 1. 并列连词不能与从属连词连用：如“although...but...”“because...so...”都是错误的，只能用其中一个。 ❌ 错误：Although he is ill, but he goes to school. ✅ 正确：Although he is ill, he goes to school. / He is ill, but he goes to school. 2. 主谓一致：either...or...、neither...nor... 遵循“就近原则”；both...and... 遵循“复数原则”；not only...but also... 遵循“就近原则”。 ✅ 例句：Neither you nor he is wrong.（就近 he，用 is）；Both you and he are wrong.（复数，用 are） 3. 宾语从句中，if 和 whether 的区别：只有 whether 能与 or not 连用、能置于句首、能作介词宾语。 ✅ 例句：I don’t care about whether he will come or not.（作介词 about 的宾语，用 whether） 4. while 的特殊用法：除了引导时间状语从句，还可表对比（而、然而），连接两个并列的句子。 ✅ 例句：She is good at English, while her brother is good at math. 5. 状语从句的“主将从现”：if、unless、as long as、when、while 等引导的状语从句，主句用一般将来时，从句用一般现在时表示将来。 ✅ 例句：If it rains tomorrow, we will stay at home.（从句 rains 用一般现在时，主句 will stay 用一般将来时） 单句填空限时训练 5 1. Both you ______ I are students. 2. Not only he ______ also his sister likes playing piano. 3. Either you ______ your friend must help me. 4. Neither my father ______ my mother likes coffee. 5. He is not a teacher ______ a doctor. 6. As soon as I ______ (arrive) in Beijing, I will call you. 7. She is ______ kind that everyone likes her. 8. It is ______ a beautiful day that we go for a walk. 9. I didn’t go to bed ______ I finished my homework. 10. He looks as if he ______ (be) tired. 11. If it ______ (rain) tomorrow, we will cancel the trip. 12. Neither you nor he ______ (be) wrong. 13. Both you and I ______ (be) good at English. 14. I don’t care about ______ he will come or not. 15. She is good at English, ______ her brother is good at math. 七、连词过关检测 1. He was tired, ___ he still continued to work. 2. Either you ___ your brother has to clean the room today. 3. I didn’t go to bed ___ I finished my homework last night. 4. ___ it rains tomorrow, we will put off the sports meeting. 5. He is young, ___ he knows a lot about history. 6. Study hard, ___ you will fail the college entrance examination. 7. I like both reading ___ writing in my spare time. 8. She must be ill, ___ she didn’t come to school. 9. ___ he is in poor health, he keeps exercising every morning. 10. I will wait here ___ you come back. 11. It was not until midnight ___ they reached the hotel. 12. You can borrow the book on condition ___ you return it on time. 13. ___ difficult the task is, we must finish it on time. 14. He hurried to school, ___ he might not be late. 15. I was about to leave ___ the phone rang. 16. She speaks English better ___ any other student in her class. 17. Many people live simply ___ they can help the poor. 18. He missed the bus, ___ he was late for the interview. 19. We will go hiking unless it ___ (rain) heavily. 20. ___ you agree or not, I will stick to my decision. 第 1 页 共 20 页 学科网（北京）股份有限公司 $ 高三英语语法专项：连词用法全解（解析版） 考点总目录 1. 连词的定义及核心特征 2. 连词的分类及基本用法（并列连词、从属连词，高三核心） 3. 高频并列连词辨析（高考易错） 4. 高频从属连词辨析（高考重难点） 5. 连词的固定搭配及特殊用法 6. 连词过关检测 一、连词的定义及核心特征 核心定义 连词（Conjunction）是用来连接词、短语、句子或从句的词，起衔接、过渡、逻辑连接的作用，无需修饰任何成分，仅负责体现前后内容的逻辑关系（如并列、转折、因果、条件等）。它是高考语法填空、短文改错、完形填空的高频考点，尤其在复合句和并列句中不可或缺，直接影响句子逻辑的连贯性和正确性。 核心特征 1. 功能定位：仅起连接作用，自身无词义（或有轻微逻辑词义），不能作句子成分（主语、谓语、宾语等），也无词形变化（无单复数、时态、人称变化）。 2. 连接对象：可连接两个词（如 A and B）、两个短语（如 go to school and play basketball）、两个句子（如 I like coffee, but she likes tea）、两个从句（如 I know that he is honest and that he works hard）。 3. 逻辑导向：每类连词都有固定的逻辑含义，如“and”表并列，“but”表转折，“because”表因果，需根据句意选择对应连词。 4. 使用禁忌：并列连词不能连接两个独立分句（除非用逗号隔开）；从属连词必须引导从句，不能单独连接两个独立句子。 特征口诀 连词无义只连接，词短语句皆可接； 无变无成分，逻辑是核心； 并列转折表并列，从属引导从句列； 固定搭配记牢固，高考做题不迷路。 单句填空限时训练 1 1. I like reading ______ writing in my free time. 2. She is tired, ______ she still keeps working. 3. He didn’t go to school ______ he was ill. 4. You will pass the exam ______ you study hard. 5. I don’t know ______ he will come or not. 6. She can speak English ______ Chinese fluently. 7. ______ it rains tomorrow, we will stay at home. 8. He is tall ______ strong. 9. I finished my homework ______ my sister watched TV. 10. She asked me ______ I could help her with her English. 11. He is not only a teacher ______ also a writer. 12. I will go to the park ______ the weather is fine. 13. She failed the exam ______ she didn’t study hard. 14. ______ you are right, I still don’t agree with you. 15. I don’t like coffee, ______ I like tea. 16. He told me ______ he would come back soon. 17. You can choose either this book ______ that one. 18. She was late ______ the traffic was heavy. 19. I will call you ______ I arrive in Beijing. 20. ______ he is young, he knows a lot. 答案 + 详细解析 1. and 解析：考查并列连词。句意“我空闲时喜欢读书和写作”，reading 和 writing 是并列关系，表“和”，用 and。 2. but 解析：考查并列连词。句意“她很累，但仍然继续工作”，前后句是转折关系，表“但是”，用 but。 3. because 解析：考查从属连词（因果关系）。句意“他没去上学，因为他生病了”，后句是前句的原因，用 because。 4. if 解析：考查从属连词（条件关系）。句意“如果你努力学习，你会通过考试”，前句是后句的条件，用 if（如果）。 5. whether 解析：考查从属连词（选择关系）。句意“我不知道他是否会来”，whether...or not 是固定搭配，表“是否”，if 不能与 or not 连用。 6. and 解析：考查并列连词。句意“她能流利地说英语和中文”，English 和 Chinese 是并列关系，表“和”，用 and。 7. If 解析：考查从属连词（条件关系）。句意“如果明天下雨，我们就待在家里”，前句是后句的条件，句首首字母大写，用 If。 8. and 解析：考查并列连词。句意“他又高又壮”，tall 和 strong 是并列描述人的特征，表“并且”，用 and。 9. while 解析：考查从属连词（对比关系）。句意“我完成作业时，我妹妹在看电视”，前后句动作同时进行，表对比，用 while（与此同时）。 10. if/whether 解析：考查从属连词（疑问关系）。句意“她问我是否能帮她学英语”，引导宾语从句，表“是否”，if 和 whether 均可。 11. but 解析：考查并列连词固定搭配。not only...but also... 是固定搭配，表“不仅……而且……”，故填 but。 12. if 解析：考查从属连词（条件关系）。句意“如果天气好，我会去公园”，前句是后句的条件，用 if。 13. because 解析：考查从属连词（因果关系）。句意“她考试不及格，因为她没有努力学习”，后句是前句的原因，用 because。 14. Although/Though 解析：考查从属连词（转折关系）。句意“虽然你是对的，但我仍然不同意你”，表“虽然”，句首首字母大写，用 Although 或 Though。 15. but 解析：考查并列连词。句意“我不喜欢咖啡，但我喜欢茶”，前后句是转折关系，用 but。 16. that 解析：考查从属连词（引导宾语从句）。句意“他告诉我他很快就会回来”，宾语从句句意完整、不缺成分，用 that 引导（that 可省略，但此处需填空，故填 that）。 17. or 解析：考查并列连词固定搭配。either...or... 是固定搭配，表“要么……要么……”，故填 or。 18. because 解析：考查从属连词（因果关系）。句意“她迟到了，因为交通很拥挤”，后句是前句的原因，用 because。 19. when 解析：考查从属连词（时间关系）。句意“我到达北京后会给你打电话”，表“当……时”，动作先后发生，用 when。 20. Although/Though 解析：考查从属连词（转折关系）。句意“虽然他很年轻，但他知道很多”，表“虽然”，句首首字母大写，用 Although 或 Though。 二、连词的分类及基本用法（并列连词、从属连词） 连词按功能可分为两大类：并列连词和从属连词，两者核心区别在于：并列连词连接“地位平等”的成分（词、短语、独立句子），从属连词连接“地位不平等”的成分（主句和从句，从句依附于主句）。 1. 并列连词（连接并列成分，无主从之分） 核心功能：连接两个或多个并列的词、短语、独立句子，体现并列、转折、选择、因果等逻辑关系，连接独立句子时，需在连词前加逗号。 常见类型及用法： 1. 表并列关系（and, both...and..., not only...but also...） ✅ 例句：She likes singing and dancing.（连接两个短语）；Both you and I are students.（连接两个人称代词）；He not only studies hard but also helps others.（连接两个谓语） 2. 表转折关系（but, yet, however） ✅ 例句：I tried my best, but I failed.（连接两个独立句子）；He is young, yet he is experienced.（yet 语气比 but 弱）；It was raining, however, we went out.（however 可置于句中、句首或句尾，需用逗号隔开） 3. 表选择关系（or, either...or..., neither...nor...） ✅ 例句：Do you like coffee or tea?（连接两个名词）；Either you leave, or I call the teacher.（连接两个句子）；Neither he nor I know the answer.（连接两个人称代词，主谓一致遵循“就近原则”） 4. 表因果关系（so, for） ✅ 例句：He was ill, so he didn’t go to school.（so 表“所以”，前因后果）；He must be ill, for he is absent today.（for 表“因为”，补充说明原因，不能置于句首） 2. 从属连词（引导从句，有主从之分） 核心功能：引导一个从句（宾语从句、状语从句、定语从句等），依附于主句，体现主句和从句之间的逻辑关系（时间、条件、因果、让步等），从句不能单独成句。 高考高频类型及用法（重点掌握状语从句和宾语从句引导词）： 1. 引导时间状语从句（when, while, as, before, after, until, since） ✅ 例句：When I arrived, he was reading.（when 可接短暂性动词或持续性动词）；While he was reading, I was writing.（while 接持续性动词，表动作同时进行）；I will call you after I finish my work.（after 表“在……之后”） 2. 引导条件状语从句（if, unless, as long as） ✅ 例句：If it rains, we will cancel the trip.（if 表“如果”）；Unless you study hard, you won’t pass the exam.（unless 表“除非”，相当于 if not）；You can succeed as long as you keep trying.（as long as 表“只要”） 3. 引导因果状语从句（because, since, as） ✅ 例句：I didn’t go out because it was raining.（because 表“因为”，回答 why 提问，可置于句首或句末）；Since you are tired, you can have a rest.（since 表“既然”，语气较弱，置于句首）；As it was late, we went home.（as 表“因为”，语气比 since 更弱） 4. 引导让步状语从句（although, though, even if, even though） ✅ 例句：Although he is poor, he is happy.（although/though 表“虽然”，不能与 but 连用）；Even if it snows, we will go to school.（even if 表“即使”，假设一种情况） 5. 引导宾语从句（that, if, whether, what, who, where 等） ✅ 例句：I know that he is a student.（that 引导陈述句宾语从句，可省略）；I wonder if/whether he will come.（if/whether 引导一般疑问句宾语从句，表“是否”）；She asked me where I went yesterday.（where 引导特殊疑问句宾语从句） 单句填空限时训练 2 1. ______ he is rich, he is not happy. 2. I will wait for you ______ you come back. 3. She can ______ sing ______ dance well. 4. He didn’t come to school, ______ he was ill. 5. I don’t know ______ he is at home or not. 6. ______ you work hard, you will get good grades. 7. He likes playing football, ______ his brother likes playing basketball. 8. I have finished my homework, ______ I can watch TV now. 9. ______ I was walking on the street, I saw an old friend. 10. She asked me ______ I had seen her keys. 11. Neither my father ______ my mother likes coffee. 12. ______ it was cold, we still went out for a walk. 13. I will call you ______ I get there. 14. He is not only tall ______ also handsome. 15. You can’t pass the exam ______ you study hard. 16. I know ______ he will come to the party. 17. Either you finish it now ______ you do it tomorrow. 18. ______ he is young, he can speak three languages. 19. I didn’t go to bed ______ I finished my homework. 20. He was late, ______ the traffic was heavy. 答案 + 详细解析 1. Although/Though 解析：考查从属连词（让步关系）。句意“虽然他很富有，但他不快乐”，表“虽然”，句首首字母大写，用 Although 或 Though，不能与 but 连用。 2. until 解析：考查从属连词（时间关系）。句意“我会等你，直到你回来”，表“直到……为止”，用 until。 3. both; and 解析：考查并列连词固定搭配。both...and... 表“既……又……”，句意“她既会唱歌又会跳舞”，符合语境。 4. because 解析：考查从属连词（因果关系）。句意“他没去上学，因为他生病了”，后句是前句的原因，用 because。 5. whether 解析：考查从属连词（宾语从句）。句意“我不知道他是否在家”，whether...or not 是固定搭配，if 不能与 or not 连用，故填 whether。 6. If/As long as 解析：考查从属连词（条件关系）。句意“如果你努力学习，你会取得好成绩”，表“如果”或“只要”，用 If 或 As long as 均可，句首首字母大写。 7. but 解析：考查并列连词（转折关系）。句意“他喜欢踢足球，但他弟弟喜欢打篮球”，前后句是转折关系，用 but。 8. so 解析：考查并列连词（因果关系）。句意“我已经完成了作业，所以现在我可以看电视了”，前因后果，用 so。 9. While/When/As 解析：考查从属连词（时间关系）。句意“当我在街上走的时候，我看到了一个老朋友”，动作同时进行或先后发生，用 While、When 或 As 均可，句首首字母大写。 10. if/whether 解析：考查从属连词（宾语从句）。句意“她问我是否看到了她的钥匙”，引导宾语从句，表“是否”，if 和 whether 均可。 11. nor 解析：考查并列连词固定搭配。neither...nor... 表“既不……也不……”，句意“我爸爸和妈妈都不喜欢咖啡”，故填 nor。 12. Although/Though/Even if 解析：考查从属连词（让步关系）。句意“虽然天气很冷，但我们仍然出去散步了”，表“虽然”或“即使”，用 Although、Though 或 Even if 均可，句首首字母大写。 13. when/after 解析：考查从属连词（时间关系）。句意“我到那里后会给你打电话”，表“当……时”或“在……之后”，用 when 或 after 均可。 14. but 解析：考查并列连词固定搭配。not only...but also... 表“不仅……而且……”，句意“他不仅高，而且帅”，故填 but。 15. unless 解析：考查从属连词（条件关系）。句意“除非你努力学习，否则你不能通过考试”，unless 表“除非”，相当于 if not，符合语境。 16. that 解析：考查从属连词（宾语从句）。句意“我知道他会来参加派对”，宾语从句句意完整、不缺成分，用 that 引导（可省略，但此处需填空，故填 that）。 17. or 解析：考查并列连词固定搭配。either...or... 表“要么……要么……”，句意“要么你现在完成它，要么你明天做”，故填 or。 18. Although/Though 解析：考查从属连词（让步关系）。句意“虽然他很年轻，但他会说三种语言”，表“虽然”，句首首字母大写，用 Although 或 Though。 19. until 解析：考查从属连词（时间关系）。句意“我直到完成作业才睡觉”，not...until... 是固定搭配，表“直到……才……”，此处前面有 didn’t，故填 until。 20. for 解析：考查并列连词（因果关系）。句意“他迟到了，因为交通很拥挤”，for 表补充说明原因，不能置于句首，符合语境。 三、高频并列连词辨析（高考易错） 高考中并列连词的易错点主要集中在“转折、选择、因果”类连词的辨析，需重点区分含义和用法差异，避免混淆。 1. 易混组1：but vs yet vs however - but：最常用，表强烈转折，连接两个并列分句，可置于分句之间，前面加逗号，后面不加逗号。 ✅ 例句：He is rich, but he is not kind. - yet：语气比 but 弱，表“然而、却”，可置于分句之间（前面加逗号），也可置于句末。 ✅ 例句：She tried hard, yet she failed.；He hasn’t come yet. - however：表“然而”，语气比 but 强，可置于句首（后面加逗号）、句中（前后加逗号）、句末（前面加逗号），不能直接连接两个分句。 ✅ 例句：However, he didn’t give up.；He tried hard, however, he failed. 2. 易混组2：so vs for - so：表“所以、因此”，前因后果，连接两个有因果关系的分句，前面加逗号，可置于分句之间。 ✅ 例句：It was raining, so we stayed at home.（下雨是原因，待在家里是结果） - for：表“因为”，补充说明原因，不能置于句首，前面加逗号，语气比 because 弱，不回答 why 提问。 ✅ 例句：We stayed at home, for it was raining.（补充说明待在家里的原因，不是直接回答 why） 3. 易混组3：either...or... vs neither...nor... vs both...and... - either...or...：表“要么……要么……”，选择关系，两者选其一，主谓一致遵循“就近原则”。 ✅ 例句：Either you or I am wrong.（谓语动词与 I 一致，用 am） - neither...nor...：表“既不……也不……”，否定选择关系，两者都不，主谓一致遵循“就近原则”。 ✅ 例句：Neither he nor his sister likes playing football.（谓语动词与 his sister 一致，用 likes） - both...and...：表“既……又……”，并列关系，两者都，主谓一致用复数。 ✅ 例句：Both my brother and I are students.（谓语动词用 are） 4. 易混组4：and vs or（并列 vs 选择） - and：表“和、并且”，并列关系，连接两个肯定的并列成分。 ✅ 例句：I like apples and bananas. - or：表“或者”，选择关系，连接两个可供选择的成分；在否定句中，or 代替 and，表“和”。 ✅ 例句：Do you like coffee or tea?（选择）；I don’t like apples or bananas.（否定句中表“和”） 单句填空限时训练 3 1. I tried my best, ______ I still failed.（but/yet/however） 2. It was raining, ______ we stayed at home.（so/for） 3. We stayed at home, ______ it was raining.（so/for） 4. ______ he is young, he is very experienced.（but/however/although） 5. Either you ______ your brother must go there.（and/or） 6. Neither you nor I ______ wrong.（am/is/are） 7. Both you and he ______ good at English.（am/is/are） 8. I don’t like coffee ______ tea.（and/or） 9. He is rich, ______ he is not happy.（but/yet/however） 10. She hasn’t finished her homework ______.（but/yet/however） 11. ______, we still have a lot of work to do.（But/Yet/However） 12. He likes playing football, ______ his brother likes playing ping-pong.（but/for） 13. Either you finish it now ______ you do it tomorrow.（and/or） 14. Neither my mother nor my father ______ watching TV.（like/likes） 15. I like singing ______ dancing.（and/or） 答案 + 详细解析 1. but/yet 解析：考查 but vs yet vs however。此处连接两个并列分句，前面加逗号，后面不加逗号，but 和 yet 均可；however 需前后加逗号，故不选。 2. so 解析：考查 so vs for。前因后果（下雨是原因，待在家里是结果），表“所以”，用 so。 3. for 解析：考查 so vs for。补充说明待在家里的原因，不能置于句首，用 for。 4. although 解析：考查 but vs however vs although。此处引导让步状语从句，表“虽然”，用 although；but 和 however 是并列连词，不能引导从句。 5. or 解析：考查 and vs or。either...or... 是固定搭配，表“要么……要么……”，故填 or。 6. am 解析：考查 neither...nor... 的主谓一致。遵循“就近原则”，靠近谓语动词的是 I，故用 am。 7. are 解析：考查 both...and... 的主谓一致。连接两个主语，谓语动词用复数，故填 are。 8. or 解析：考查 and vs or。否定句中，or 代替 and 表“和”，句意“我不喜欢咖啡和茶”，故填 or。 9. but/yet 解析：考查 but vs yet vs however。连接两个并列分句，前面加逗号，后面不加逗号，but 和 yet 均可。 10. yet 解析：考查 but vs yet vs however。yet 可置于句末，表“还、尚未”，句意“她还没完成作业”，故填 yet。 11. However 解析：考查 But vs Yet vs However。置于句首，后面加逗号，表“然而”，用 However；But 和 Yet 不能置于句首且单独使用（需连接分句）。 12. but 解析：考查 but vs for。前后句是转折关系（他喜欢足球，弟弟喜欢乒乓球），用 but；for 表因果，不符合语境。 13. or 解析：考查 and vs or。either...or... 是固定搭配，表“要么……要么……”，故填 or。 14. likes 解析：考查 neither...nor... 的主谓一致。遵循“就近原则”，靠近谓语动词的是 my father，第三人称单数，故用 likes。 15. and 解析：考查 and vs or。并列关系，表“和”，句意“我喜欢唱歌和跳舞”，故填 and。 四、高频从属连词辨析（高考重难点） 从属连词是高三英语语法的核心重难点，尤其是时间、条件、让步、因果类从属连词，高考中常结合复合句考查，需重点区分含义、用法及易错点。 1. 易混组1：when vs while vs as（时间状语从句） - when：最常用，可引导短暂性动词（如 arrive, leave）或持续性动词（如 read, work），表“当……时”，动作可先后发生或同时发生。 ✅ 例句：When he arrived, we were having dinner.（短暂性动词，先后发生）；When we were reading, he came in.（持续性动词，同时发生） - while：只能引导持续性动词，表“在……期间”，强调两个动作同时进行；也可表对比，意为“而、然而”。 ✅ 例句：While she was cooking, I was cleaning the room.（同时进行）；He likes playing football, while his brother likes playing basketball.（对比） - as：表“当……时”，强调两个动作同时进行，语气比 while 弱，也可表“随着”。 ✅ 例句：As I was walking, I saw a dog.（同时进行）；As time goes by, we grow up.（随着） 2. 易混组2：if vs unless vs as long as（条件状语从句） - if：表“如果”，引导肯定条件，主句用一般将来时，从句用一般现在时（主将从现）。 ✅ 例句：If it rains tomorrow, we will not go out. - unless：表“除非”，相当于“if not”，引导否定条件，主句用一般将来时，从句用一般现在时。 ✅ 例句：Unless you study hard, you won’t pass the exam.（= If you don’t study hard, you won’t pass the exam.） - as long as：表“只要”，引导条件，语气比 if 强，强调“只要满足某个条件，就会产生某个结果”。 ✅ 例句：As long as you keep trying, you will succeed. 3. 易混组3：because vs since vs as（因果状语从句） - because：表“因为”，语气最强，直接说明原因，可置于句首或句末，能回答 why 提问。 ✅ 例句：Why didn’t you go? Because I was ill. - since：表“既然”，语气较弱，引导的原因是已知的、显而易见的，置于句首。 ✅ 例句：Since you are free, you can help me with my homework. - as：表“因为”，语气最弱，引导的原因是补充说明的，可置于句首或句中，不如 because 和 since 强调原因。 ✅ 例句：As it was getting dark, we decided to go home. 4. 易混组4：although/though vs even if/even though（让步状语从句） - although/though：表“虽然、尽管”，两者用法基本一致，though 可置于句末，although 不能；均不能与 but 连用。 ✅ 例句：Although/Though he is short, he is very strong.；He is short, though he is very strong. - even if/even though：表“即使、纵然”，语气比 although/though 强，引导的是假设的、不太可能发生的情况。 ✅ 例句：Even if it snows heavily, we will go to school.（假设下雪的情况，不一定会发生） 5. 易混组5：that vs if/whether（宾语从句） - that：引导陈述句宾语从句，句意完整、不缺成分，that 可省略（填空时需根据语境判断是否需要填写）。 ✅ 例句：I think (that) he is right. - if/whether：引导一般疑问句宾语从句，表“是否”，两者可互换，但以下情况只能用 whether：① 与 or not 连用；② 置于句首；③ 作介词宾语。 ✅ 例句：I wonder if/whether he will come.；I don’t know whether he will come or not.（只能用 whether） 单句填空限时训练 4 1. ______ I was reading a book, my brother was watching TV.（when/while/as） 2. ______ he arrived at the station, the train had left.（when/while/as） 3. ______ time goes by, our friendship becomes stronger.（when/while/as） 4. You will succeed ______ you keep trying.（if/unless/as long as） 5. ______ you don’t study hard, you won’t pass the exam.（if/unless/as long as） 6. ______ it rains, we will cancel the trip.（if/unless/as long as） 7. ______ you are tired, you can have a rest.（because/since/as） 8. I didn’t go out ______ it was raining.（because/since/as） 9. ______ it was late, we went on working.（because/since/as） 10. ______ he is poor, he is very kind.（although/even if） 11. ______ it snows, we will go to school.（although/even if） 12. I know ______ he will come to the party.（that/if/whether） 13. I wonder ______ he will come or not.（that/if/whether） 14. ______ he will come is not sure.（that/if/whether） 15. He likes playing football, ______ his brother likes playing basketball.（when/while/as） 答案 + 详细解析 1. while/as 解析：考查 when vs while vs as。前后两个动作（reading 和 watching TV）都是持续性动词，同时进行，用 while 或 as；when 可接短暂性动词，此处不优先选。 2. when 解析：考查 when vs while vs as。arrived 是短暂性动词，表“当……时”，动作先后发生（到达时火车已经开走），用 when；while 和 as 不能接短暂性动词。 3. as 解析：考查 when vs while vs as。表“随着时间的流逝”，用 as；when 和 while 无“随着”的含义。 4. as long as/if 解析：考查 if vs unless vs as long as。句意“只要你坚持尝试，你就会成功”，表“只要”用 as long as，表“如果”用 if，均可，as long as 语气更强。 5. if/unless 解析：考查 if vs unless vs as long as。句意“如果你不努力学习，你就不能通过考试”，用 if 表“如果”，或用 unless 表“除非”（相当于 if not），均可。 6. if 解析：考查 if vs unless vs as long as。句意“如果下雨，我们就取消旅行”，表肯定条件，用 if；unless 表否定条件，as long as 表“只要”，不符合语境。 7. since/as 解析：考查 because vs since vs as。句意“既然你累了，你可以休息一下”，原因是已知的，用 since 或 as；because 语气太强，不适合此处语境。 8. because 解析：考查 because vs since vs as。句意“我没出去，因为下雨了”，直接说明原因，可回答 why 提问，用 because。 9. since/as 解析：考查 because vs since vs as。句意“虽然天晚了，但我们继续工作”，此处表“因为”（补充说明原因），用 since 或 as；because 语气太强，不符合语境。 10. although 解析：考查 although vs even if。句意“虽然他很穷，但他很善良”，表“虽然”，描述客观事实，用 although；even if 表“即使”，引导假设情况，不符合语境。 11. even if 解析：考查 although vs even if。句意“即使下雪，我们也会去上学”，表“即使”，引导假设的情况（不一定下雪），用 even if；although 表客观事实的转折，不符合语境。 12. that 解析：考查 that vs if/whether。宾语从句句意完整、不缺成分，用 that 引导（可省略，但此处需填空，故填 that）；if/whether 表“是否”，不符合语境。 13. whether 解析：考查 that vs if/whether。与 or not 连用，只能用 whether，不能用 if；that 无“是否”含义，故填 whether。 14. whether 解析：考查 that vs if/whether。置于句首引导主语从句，表“是否”，只能用 whether，不能用 if；that 无“是否”含义，故填 whether。 15. while 解析：考查 when vs while vs as。表对比，意为“而、然而”，句意“他喜欢踢足球，而他弟弟喜欢打篮球”，用 while；when 和 as 无对比含义。 五、连词的固定搭配及特殊用法 1. 常见固定搭配（高考高频） - 并列连词固定搭配： - both...and... 既……又…… → Both she and I are good at English. - not only...but also... 不仅……而且…… → He not only reads books but also writes articles. - either...or... 要么……要么…… → Either you come, or I go. - neither...nor... 既不……也不…… → Neither he nor she likes swimming. - not...but... 不是……而是…… → He is not a teacher but a doctor. - 从属连词固定搭配： - as soon as 一……就…… → As soon as I get home, I will call you. - so...that... 如此……以至于…… → She is so kind that everyone likes her. - such...that... 如此……以至于…… → It is such a beautiful day that we go for a walk. - not...until... 直到……才…… → I didn’t go to bed until I finished my homework. - as if/as though 好像、似乎 → He looks as if he is tired. 2. 特殊用法及易错点 1. 并列连词不能与从属连词连用：如“although...but...”“because...so...”都是错误的，只能用其中一个。 ❌ 错误：Although he is ill, but he goes to school. ✅ 正确：Although he is ill, he goes to school. / He is ill, but he goes to school. 2. 主谓一致：either...or...、neither...nor... 遵循“就近原则”；both...and... 遵循“复数原则”；not only...but also... 遵循“就近原则”。 ✅ 例句：Neither you nor he is wrong.（就近 he，用 is）；Both you and he are wrong.（复数，用 are） 3. 宾语从句中，if 和 whether 的区别：只有 whether 能与 or not 连用、能置于句首、能作介词宾语。 ✅ 例句：I don’t care about whether he will come or not.（作介词 about 的宾语，用 whether） 4. while 的特殊用法：除了引导时间状语从句，还可表对比（而、然而），连接两个并列的句子。 ✅ 例句：She is good at English, while her brother is good at math. 5. 状语从句的“主将从现”：if、unless、as long as、when、while 等引导的状语从句，主句用一般将来时，从句用一般现在时表示将来。 ✅ 例句：If it rains tomorrow, we will stay at home.（从句 rains 用一般现在时，主句 will stay 用一般将来时） 单句填空限时训练 5 1. Both you ______ I are students. 2. Not only he ______ also his sister likes playing piano. 3. Either you ______ your friend must help me. 4. Neither my father ______ my mother likes coffee. 5. He is not a teacher ______ a doctor. 6. As soon as I ______ (arrive) in Beijing, I will call you. 7. She is ______ kind that everyone likes her. 8. It is ______ a beautiful day that we go for a walk. 9. I didn’t go to bed ______ I finished my homework. 10. He looks as if he ______ (be) tired. 11. If it ______ (rain) tomorrow, we will cancel the trip. 12. Neither you nor he ______ (be) wrong. 13. Both you and I ______ (be) good at English. 14. I don’t care about ______ he will come or not. 15. She is good at English, ______ her brother is good at math. 答案 + 解析 1. and 解析：固定搭配 both...and...，表“既……又……”。 2. but 解析：固定搭配 not only...but also...，表“不仅……而且……”。 3. or 解析：固定搭配 either...or...，表“要么……要么……”。 4. nor 解析：固定搭配 neither...nor...，表“既不……也不……”。 5. but 解析：固定搭配 not...but...，表“不是……而是……”。 6. arrive 解析：考查“主将从现”，as soon as 引导的时间状语从句，主句用一般将来时，从句用一般现在时，故填 arrive。 7. so 解析：固定结构 so + 形容词 + that 从句，表“如此……以至于……”。 8. such 解析：固定结构 such + a/an + 形容词 + 单数名词 + that 从句，表“如此……以至于……”。 9. until 解析：固定搭配 not...until...，表“直到……才……”。 10. is 解析：as if 引导的从句，表虚拟语气，此处描述现在的状态，用一般现在时，主语是 he，故填 is。 11. rains 解析：考查“主将从现”，if 引导的条件状语从句，主句用一般将来时，从句用一般现在时，故填 rains。 12. is 解析：neither...nor... 遵循“就近原则”，靠近谓语动词的是 he，第三人称单数，故填 is。 13. are 解析：both...and... 遵循“复数原则”，连接两个主语，谓语动词用复数，故填 are。 14. whether 解析：作介词 about 的宾语，且与 or not 连用，只能用 whether。 15. while 解析：while 表对比，意为“而、然而”，连接两个并列的句子，符合语境。 七、连词过关检测 1. He was tired, ___ he still continued to work. 2. Either you ___ your brother has to clean the room today. 3. I didn’t go to bed ___ I finished my homework last night. 4. ___ it rains tomorrow, we will put off the sports meeting. 5. He is young, ___ he knows a lot about history. 6. Study hard, ___ you will fail the college entrance examination. 7. I like both reading ___ writing in my spare time. 8. She must be ill, ___ she didn’t come to school. 9. ___ he is in poor health, he keeps exercising every morning. 10. I will wait here ___ you come back. 11. It was not until midnight ___ they reached the hotel. 12. You can borrow the book on condition ___ you return it on time. 13. ___ difficult the task is, we must finish it on time. 14. He hurried to school, ___ he might not be late. 15. I was about to leave ___ the phone rang. 16. She speaks English better ___ any other student in her class. 17. Many people live simply ___ they can help the poor. 18. He missed the bus, ___ he was late for the interview. 19. We will go hiking unless it ___ (rain) heavily. 20. ___ you agree or not, I will stick to my decision. 答案 + 详细解析 1、but解析：并列连词，表转折。句意：他很累，但依然继续工作。 and（顺承）、but（转折）、so（结果）、or（否则）为高考高频并列连词。 2、or解析：固定搭配 either...or... 要么…… 要么……，就近一致原则。句意：要么你，要么你弟弟今天打扫房间。 3、until/till 解析：固定结构 not...until... 直到…… 才……。句意：昨晚我直到写完作业才睡觉。 4、If 解析：条件状语从句引导词，if 引导真实条件句，遵循 “主将从现”。句意：如果明天下雨，我们就推迟运动会。 5、though/although 解析：让步连词，表 “虽然”。句意：他年纪小，却懂很多历史知识。though/although 不能与 but 连用。 6、or 解析：or 此处意为 “否则，要不然”。句意：努力学习，否则你高考会失利。 7、and 解析：固定搭配 both...and... 两者都……。句意：业余时间我既喜欢阅读也喜欢写作。 8、for 解析：并列连词 for，表补充说明原因，不能置于句首。句意：她一定生病了，因为她没来上学。 9、Although/Though 解析：让步状语从句，意为 “尽管”。句意：尽管身体不好，他依然每天晨练。 10、until/till 解析：引导时间状语从句，意为 “直到…… 为止”。句意：我会一直在这等你回来。 11、that 解析：强调句型 It was not until...that... 固定连词结构，高考高频考点。句意：直到午夜他们才到达酒店。 12、that 解析：固定连词搭配 on condition that 条件是……。句意：你可以借这本书，条件是按时归还。 13、However 解析：however + 形容词 / 副词，引导让步状语从句，意为 “无论多么……”。句意：无论任务多难，我们必须按时完成。 14、so that 解析：so that 引导目的状语从句，意为 “为了”。句意：他匆忙赶往学校，为了不迟到。 15、when 解析：固定句式 be about to do...when... 正要做…… 突然……。句意：我正要离开，电话突然响了。 16、than 解析：比较连词，用于比较级之后，表 “比”。句意：她的英语说得比班里其他同学都好。 17、so that 解析：目的状语从句，表行为的目的。句意：很多人生活简朴，只为帮助穷人。 18、so 解析：并列连词，表因果，意为 “因此、所以”。句意：他错过了公交，所以面试迟到了。 19、rains 解析：unless（除非）引导条件状语从句，主将从现，主语 it 为单数，谓语用 rains。 20、Whether 解析：固定搭配 whether...or not 无论是否……，引导让步状语从句。句意：无论你是否同意，我都会坚持自己的决定。 第 1 页 共 20 页 学科网（北京）股份有限公司 $