基础动词用法 情态动词系统讲解-2025-2026学年高考复习高中英语语法知识点全解（沪外版）

高中沪外版 【语法专版】 基础动词用法 语法专版 【专题】情态动词系统讲解 沪外版高中英语语法全解 考频分析 沪外版高中英语中，情态动词是基础动词用法的重点语法模块，考频占词法总量的15%左右，贯 穿试卷所有核心题型：单项选择2-3题、完形填空2-3题、语法填空1-2题、书面表达核心考察，直 接影响句子完整性与准确性。在语境理解类题目中，情态动词的语气表达、情态意义辨析及虚拟用 法往往是解题关键。 考查内容 。基本词义与功能：can/could(能力、许可、推测)、may/might(许可、推测、可能性)、must/have to (必须、推测)、shall/should(义务、建议、推测)、will/would(意愿、习惯、推测)的核心语义辨析 ·推测用法：不同情态动词表推测时在肯定句、否定句、疑问句中的语气差异（如ust用于肯定推 测，can't用于否定推测，may/might用于可能性推测)及与不同时态的搭配（如对现在情况的推测 用“情态动词+动词原形”，对过去情况的推测用“情态动词+have+过去分词”) 。虚拟语气关联：与虚拟语气结合使用的情态动词（如should have done表“本应该做却未做”，could have done表“本能够做却未做”)及语境中的隐含意义判断 知识点一：情态动词的基本含义及用法 l.can/could（能力/许可/推测) 1.基本含义：can表现在或一般能力、许可：could为过去式，表过去能力、委婉请求或可能性较小的 推测 2.例句： ·I can speak English fluently.(表能力) ·Could you please open the window?(委婉请求) 。It could rain tomorrow.(推测，可能性较低) 2.may/might(许可/推测) 高中沪外版 【语法专版】 基础动词用法 1.基本含义：may表许可或可能性较大的推测：might语气更委婉，可能性比may小 2.例句： ·You may leave the classroom now.(表许可) ●She might be at home.(推测，可能性较小) 3.must/have to(必须/肯定推测) 1.基本含义：must表主观必须或肯定推测（用于肯定句）：have to表客观需要，有人称、时态变化 2.例句： ◆We must follow the school rules.(主观必须) ·He has to work late tonight.(客观需要) ●This must be your book.(肯定推测) 4.should/ought to(建议/义务/推测) 1.基本含义：should表建议、义务或合理推测：ought to语气略强，意为“应该” 2.例句： ●You should study harder for the exam.(表建议) ·They ought to arrive by now.(推测，“按道理应该”) 5.will/would(意愿/习惯/推测) 1.基本含义：wll表现在意愿、将来时或固有性质：wold表过去习惯、委婉请求或过去将来时 2.例句： ·I will help you with your homework.(表意愿) ·She would often go for a walk after dinner.(过去习惯) 知识点二：情态动词基本用法与常见搭配 l.can/could(能力、许可、推测) 1.基本含义 ·ca:表示现在或一般能力(“能，会”)、口语许可(“可以”)、否定推测(“不可能”，用于否定 句) ●could:表示过去能力(“过去能”)、委婉请求(“可以吗”)、可能性推测(“可能”，语气比can 弱) 高中沪外版 【语法专版】 基础动词用法 2.句型结构 ·肯定句：主语+can/could+动词原形 。否定句：主语+can’t/couldn’t+动词原形 ·疑问句：Can/Could+主语+动词原形？ 3.例句 。She can speak three languages.(现在能力) ●Could you pass me the pen?(委婉请求) 。HIe can't be at home now.(否定推测) ·They could swim when they were five..(过去能力) 2.may/might(许可、可能性推测) 1.基本含义 。my:表示正式许可(“可以”)、肯定推测(“可能”，用于肯定句) ·might:表示可能性推测(“或许，可能”，语气比may弱)、过去许可(“过去可以”") 2.句型结构 ·肯定句：主语+may/might+动词原形 。否定句：主语+may not/might not+动词原形(may not表“不允许”，might not表“可能不”) ·疑问句：May+主语+动词原形？（表请求许可） 3.例句 ·You may leave the room now.(正式许可) 。It might rain tomorrow.(可能性推测，语气弱) ·May I use your dictionary?(请求许可) ·She might not come to the party..(可能不) 3.must/have to(必须、肯定推测) 1.基本含义 。ust:表示主观必须(“必须”，强调说话人意愿)、肯定推测(“一定”，用于肯定句) ·have to:表示客观需要(“不得不”，强调外界要求)，过去式为had to 2.句型结构 ●肯定句：主语+must/have to+动词原形 。否定句：主语+mustn't(禁止)/don’thave to(不必)+动词原形 3 高中沪外版 【语法专版】 基础动词用法 。疑问句：Must+主语+动词原形？（否定回答用needn't或don'thave to) 3.例句 ●We must obey the traffic rules..(主观必须) ·He has to work late today.(客观需要) 。This must be your book.(肯定推测) ●You mustn’t smoke here.(禁止) ·一Must I finish it now?一No,you needn't.（否定▣答) 4.need/had better(需要、建议) 1.need的用法（情态动词/实义动词） ·情态动词（多用于否定句/疑问句）：主语+needn't+动词原形(“不必”)：Need+主语+动词 原形？(“需要吗”) 。实义动词（有人称时态变化）：主语+need to do sth.(“需要做某事”)：否定句：主语+don’t need to do sth 2.had better的用法（表建议，“最好") 。结构：主语+had better(ot)+动词原形(had可缩写为'd) 3.例句 ·You needn't wait for me.(情态动词，不必) 。She needs to buy a new bag.(实义动词，需要) ·You'd better study hard for the exam.(建议做某事) 。We had better not go out in the rain.(建议不做某事) 5.should/ought to（应该、责任) 1.基本含义 。should:表示责任义务(“应该”)、建议(“应当”)、推测(“按理说”) ·ought to:含义与should基本相同，语气稍正式，结构为ought to+动词原形 2.句型结构 ●肯定句：主语+should/ought to+动词原形 。否定句：主语+shouldn't/ought not to+动词原形 ●疑问句：Should+主语+动词原形？ 3.例句 。You should help your parents with housework.(责任义务) 4 高中沪外版 【语法专版】 基础动词用法 。He ought to arrive here on time.(应当) ●It should be sunny tomorrow.(推测) 。Should we tell him the truth?(疑问句) 6.wil/would（意愿、习惯、请求) 1.will的用法 。表意愿(“愿意”)：I will help you. ●表习惯性动作(“总是”，用于第三人称)：She will often go for a walk after dinner. 。表请求（多用于第二人称，“.…好吗”）：Will you please open the window? 2.would的用法 。表过去意愿(“过去愿意")：He would always help others when he was young. ●表委婉请求（比will更客气）：Would you like some tea? 。表过去习惯性动作(“过去常常”)：They would play games together on weekends. 3.例句 ·I will never forget this day..(意愿) 。Would you mind closing the door?(委婉请求) ●She would get up early when she was in college..(过去习惯) 知识点三：情态动词 1.基础含义与用法（中考必背） 1.can（能/会/可以)→例句：I can speak English and Chinese. 2.may(可以/何能)→例句：May I borrow your pen? 3.must(必须/一定)→例句：You must finish your homework first 4.should(应该)→例句：We should help each other.. 5.will(将要/愿意)→例句：I will go to the party tomorrow. 6.would(将要/愿意，will的过去式)→例句：She said she would call me. 7.need(需要)→例句：You needn't worry about me. 8.have to(不得不，强调客观)→例句：I have to leave now because it'slate. 2.否定形式与疑问结构（中考核心） 1.否定形式： 高中沪外版 【语法专版】 基础动词用法 ·can't(不能/不可能)→例句：He can't swim across the river. ●mustn't(禁止)→例句：You mustn't park here. 。shouldn't(不应该)→例句：You shouldn't eat too much candy.. 2.疑问结构： 。Can.?(能…吗)→例句：Can you play the guitar? 。Must.?（必须…吗)→例句：Must I hand in the homework today2 。Should..?(应该…吗)→例句：Should we start the meeting now? 3.情态动词表推测（中考易错） 1.must（肯定推测，用于肯定句)→例句：He must be at home now. 2.may/might(可能推测，may可能性更大)→例句：She may come to the party tonight. 3.can't(否定推测，不可能)一例句：That can't be our teacher.He is in Beijing. 4.could(委婉推测，用于过去或现在)→例句：This book could be Lucy's. 考法精析 考法一：情态动词基本含义及用法辨析 核心：根据语境判断情态动词表达的能力、许可、推测、义务等基本含义，选择正确情态动词 真题1（语法填空）： She_speak three languages when she was five years old. 答案：could 解析：由时间标志词“when she was five years old'”可知，动作发生在过去，表过去的能力，用could。 真题2（完形填空)： -I borrow your dictionary? -Sure,here you are. A.Must B.Should C.May D.Will 答案：C 解析：根据语境“请求借用字典”，表许可的委婉请求，用May。Must表必须，Should表建议，Wil 表意愿，均不符合语境。 考法二：情态动词推测用法及时态呼应 核心：结合语境判断推测的时间（现在/过去/将来），选择正确的情态动词形式及对应的动词时态 真题1（语法填空)： The ground is dry now,so it _(rain)last night. 答案：can't have rained 6 高中沪外版 【语法专版】 基础动词用法 解析：对过去情况的否定推测，根据“last night'”可知用“情态动词+have done”结构，否定推测 需用can't have done,意为“不可能下过雨”。 真题2（完形填空）： -Where is Lucy?She isn't in the classroom -She_in the library.I saw her go there just now. A.must be B.may be C.can't be D.must have been 答案：A 解析：对现在情况的肯定推测，根据“now”及“saw her go0 there just now”的语境提示，用“must+ 动词原形”表可能性极高的推测，意为“一定在”。 考法三：情态动词推测用法及时态呼应 核心：结合不同时态（现在/过去/将来），运用情态动词(must/may/might/can't等)进行合理推测， 掌握“情态动词+动词原形nave done”的结构及语气差异 真题1（单项选择）： The light is off.She be at home now. A.must B.may C.can't D.should 答案：C 解析：根据“灯关着”的语境，对现在情况进行否定推测，需用cn't+动词原形，表“不可能”，符 合“can'tdo”表现在否定推测的用法（可能性<I0%)。 真题2（语法填空）： He_(finish)the work yesterday.He told me he had a lot of free time. 答案：must have finished 解析：根据时间标志词“yester day”及“有空余时间”的语境，对过去情况进行肯定推测，用“must have done”结构，表示“一定完成了”，符合对过去肯定推测的用法（可能性>90%）。 解题小妙招 情态动词解题妙招 基本含义看语境，能力许可义务辨：过去能力用could,请求许可may当先。 推测用法分时态，现在do过去have done;肯定must可能性高，否定推测can't添。 综合时态要呼应，must否定用can't:may not might not表可能不，时间标志是关键。 真题演练 演练一：单项选择（共10题） 1.The light is on.He_be at home now. A.must B.may C.can't D.should 7 高中沪外版 【语法专版】 基础动词用法 答案：A 2.I borrow your pen? A.Must B.Should C.May D.Will 答案：C 3.The ground is dry.Itlast night. A.must rain B.mayrain C.should rain D.can't have rained 答案：D 4.You harder for the exam.You failed it. A.must study B.should have studied C.may study D.can study 答案：B 5.-Must I finish the work today? -No,you. A.needn't B.mustn't C.shouldn't D.can't 答案：A 6.When he was young,he-get up early. A.will B.would C.wouldn't D.can't 答案：C 7.It_rain tomorrow,so take an umbrella. A.must B.might C.can't D.should 答案：B 8.According to the timetable,the train_at 8:30 A.must be B.may be C.can't be D.should be 答案：A 9.-you help me carry this box? A.Must B.Should C.May D.Could 答案：D 10.Youtake photos in the museum. A.mustn't B.needn't C.shouldn't D.may not 答案：D 演练二：填空（共10题） 1.She一play the piano when she was ten.(过去能力) 答案：could 2.That_be Tom.He is abroad now.(否定推测) 答案：can't 3.We_follow the rules.(主观必须) 答案：nust 8 高中沪外版 【语法专版】 基础动词用法 4.You_drink more water.(建议) 答案：should 5.You_leave now.(许可 答案：may 6.You_wait for me.I'll be late.(不必) 答案：needn't 7.He一go to the park every Sunday.(过去习惯) 答案：would 8.She_the bus.That's why she is late.(可能错过) 答案：might have missed 9.I_swim.(能力否定) 答案：can't l0.You一me earlier.(本应该告诉) 答案：should have told 演练三：语法填空（共10题） 1.This bag_be Lily's.It has her name on it. 答案：must 2.I can't find my keys.Ithem in the wrong place. 答案：might have put 3.He finish the work alone.It was too difficult. 答案：can't have finished 4.The meeting-start on time. 答案：should 5.You-buy a gift.I already have one 答案：needn't have bought 6.She_speak Chinese when she was a child. 答案：could 7.It_rain later,so take an umbrella. 答案：may 8.My grandfather-tell us stories about his childhood. 答案：would 9.You_hand in your homework on time. 答案：nust 10.-I use your dictionary? 答案：Can 9 高中沪外版 【语法专版】 基础动词用法 答案解析 演练一：单项选择 1.A.must 解析：根据“看到灯亮着”，对现在情况的肯定推测，用ust(一定)。 2.C.May 解析：请求许可（借钢笔），用May表委婉请求。 3.D.can'thave rained 解析：对过去情况的否定推测（地面干燥），用can't have done。. 4.B.should have studied 解析：“本应该做却未做”，表责备，用should have done。 5.A.needn't 解析：must的否定回答用need't(不必)。 6.C.wouldn't 解析：描述过去习惯（过去不愿早起），用wouldn't。 7.B.might 解析：对将来的可能性推测（可能性较低），用night。 8.A.must be 解析：对现在情况的肯定推测（根据时间表），用must be。 9.D.Could 解析：委婉请求（帮忙搬箱子），用Could。 10.C.may not 解析：表许可的否定（不允许拍照），用may not。. 演练二：填空 1.could 解析：过去的能力（十岁时会弹钢琴），用could。 2.can't 解析：对现在的否定推测（不可能是汤姆，他在国外），用can’t。 3.must 解析：主观必须（遵守规则)，用must。 4.should 解析：建议（多喝水），用should。 10