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中考英语核心语法:be adj.to do三大结构精讲精练
序言
在初中英语中,“be adj. to do”结构是高频考点,广泛应用于单选、完形、填空及书面表达中。该结构核心是通过“系动词+形容词+不定式”的组合,表达情感、事物属性或特定意愿/能力。本次讲义将围绕三大核心结构,结合中考考点补充用法细节、易错点提示,保留原全部内容,新增适配中考的强化训练,助力高效复习。
一、情感驱动类
1.结构定义:be + 情感形容词 + to do ,不定式作原因状语,表“因做某事而产生某种情感”,主语多为人(少数情况下可用it作形式主语,如nice)。
2.中考易错提示:此类形容词后接不定式时,无需加介词,直接用“be adj. to do”;部分形容词(如glad、pleased)可与“be adj. with sth.”替换,但接动作时必须用不定式。
1. happy 高兴的 be happy to do
She is happy to accept the invitation.(她很高兴接受邀请。)
中考拓展:可替换为be pleased to do,书面表达中互换可提升句式多样性。
2. glad 乐意的 be glad to do
We are glad to see you again.(我们很高兴再次见到你。)
中考常用搭配:I'm glad to hear that.(听到这个消息我很高兴。)—— 情景交际高频句。
3. pleased 愉快的 be pleased to do
He is pleased to win the match.(他很高兴赢得比赛。)
易错点:勿混淆pleased(修饰人,表“感到愉快的”)与pleasant(修饰物,表“令人愉快的”),如It's a pleasant trip.(不用pleased)。
4. nice 愉快的;美好的 be nice to do
It is nice to walk in the park.(在公园里散步很惬意。)
用法提示:此处it为形式主语,真正主语是后面的不定式,属于情感类中的特殊情况,中考常考此句式。
5. satisfied 满意的 be satisfied to do
They are satisfied to finish the task on time.(他们对按时完成任务感到满意。)
中考补充:更常用搭配be satisfied with sth./sb.(对某事/某人满意),如She is satisfied with her grades.。
6. sad 难过的 be sad to do
She is sad to hear the bad news.(听到这个坏消息,她很伤心。)
用法提示:不定式表原因,可改写为She is sad because she hears the bad news.,便于理解。
7. sorry 抱歉的;遗憾的 be sorry to do
I am sorry to interrupt you.(很抱歉打扰你。)
中考高频:I'm sorry to hear that.(听到这个我很遗憾。)—— 安慰场景必备句;be sorry for sth.(为某事道歉)。
8. excited 兴奋的 be excited to do
The kids are excited to go to the zoo.(孩子们对去动物园感到兴奋。)
易错点:区分excited(修饰人,表“感到兴奋的”)与exciting(修饰物,表“令人兴奋的”),如It's an exciting trip.。
二、事情属性类
1.结构定义:be + 属性形容词 + to do ,不定式作主语补足语(主语为物时)或真正主语(用it作形式主语时),表“某事具有某种属性”。
2.中考核心考点:1. 形式主语it的用法(高频单选考点);2. 主语为物时,不定式用主动形式表被动含义(如The book is easy to read. 不用to be read)。
1. easy 容易的 be easy to do
This book is easy to read. It is easy to read this book.(这本书容易读。)
3.中考提示:后句为高频句式,it作形式主语,真正主语是to read this book,书面表达中用此句式可避免头重脚轻。
2. difficult 困难的 be difficult to do
The problem is difficult to solve. It is difficult to solve the problem.(这个问题很难解决。)
易错点:勿在不定式前加for sb. 以外的介词,正确表达为It is difficult for us to solve the problem.(for sb. 表不定式的逻辑主语)。
3. hard 艰难的 be hard to do
The job is hard to finish. It is hard to finish the job.(这份工作很难完成。)
中考辨析:hard作形容词时表“艰难的”,作副词时表“努力地”,注意语境区分,如work hard(副词)、a hard job(形容词)。
4. important 重要的 be important to do
It is important to learn English well.(学好英语很重要。)
中考必背:常用搭配It is important for sb. to do sth.(对某人来说做某事很重要),如It is important for us to keep healthy.。
5. necessary 必要的 be necessary to do
It is necessary to take medicine on time.(按时吃药是必要的。)
补充用法:It is necessary for sb. to do sth.(某人有必要做某事),如It is necessary for you to hand in homework on time.。
6. possible 可能的 be possible to do
It is possible to get there on time.(按时到达那里是可能的。)
中考易错:possible不能用于“sb. be possible to do”结构,只能用It is possible for sb. to do sth.,如It is possible for her to pass the exam.(不能说She is possible to pass...)。
7. impossible 不可能的 be impossible to do
It is impossible to finish the work in one day.(一天内完成这项工作是不可能的。)
用法提示:反义词为possible,用法一致,同样需用it作形式主语。
8. interesting 有趣的 be interesting to do
This game is interesting to play. It is interesting to play this game.(这个游戏玩起来很有趣。)
易错点:区分interesting(修饰物,表“令人有趣的”)与interested(修饰人,表“对……感兴趣的”),如She is interested in this game.。
三、特殊句型类
1.结构定义:固定形容词短语 + to do ,表能力、意愿、可能性、渴望等特定含义,均为中考高频固定搭配,需熟练背诵。
2.中考提示:此类结构无灵活变化,需牢记形容词与不定式的固定组合,避免混淆含义(如be able to 与 be willing to 的区别)。
1. be able to 能够 be able to do
He is able to speak three languages.(他能说三种语言。)
中考辨析:与can同义,can无不定式形式,且be able to 可用于各种时态,如He will be able to finish it tomorrow.(can不能用于将来时的这种结构)。
2. be willing to 愿意 be willing to do
She is willing to help others.(她愿意帮助别人。)
补充搭配:be willing to do sth. for sb.(愿意为某人做某事),书面表达中可用于描写人物品质。
3. be ready to 准备好;乐意 be ready to do
We are ready to start the journey.(我们准备好开始旅程了。)
中考高频:be ready to help others(乐于助人),常用于作文中人物描写;还可表示“一……就……”,如She is ready to cry when she hears the story.。
4. be likely to 可能 be likely to do
It is likely to rain this evening.(今晚可能会下雨。)
用法提示:可用于“sb./sth. be likely to do”或“It is likely to do”两种结构,如He is likely to come.(他可能会来。),区别于possible的用法。
5. be unlikely to 不太可能 be unlikely to do
He is unlikely to come to the party.(他不太可能来参加派对。)
补充:反义词为be likely to,用法一致,可用于否定句改写,如It is unlikely for him to pass the exam.。
6. be eager to 渴望 be eager to do
The students are eager to learn new things.(学生们渴望学习新事物。)
中考搭配:be eager for sth.(渴望某物),如She is eager for success.(她渴望成功。)。
7. be afraid to 害怕 be afraid to do
She is afraid to walk alone at night.(她害怕晚上独自走路。)
中考辨析:be afraid to do 表“害怕做某事(因担心有不好结果)”;be afraid of doing 表“担心发生某事”,如She is afraid of falling down.(担心摔倒)。
四、基础巩固练习
(一)用所给动词的适当形式填空
She is very glad ________ (receive) your birthday gift.
It is important ________ (obey) the traffic rules on the road.
This machine is easy ________ (operate) even for beginners.
They are willing ________ (donate) money to the poor mountain area.
It is likely ________ (snow) heavily tomorrow morning.
We are sorry ________ (tell) you that the concert is canceled.
This story is interesting ________ (read) for children.
He is able ________ (swim) across the river when he was 10.
It is necessary for us ________ (study) hard for the exam.
She is eager ________ (visit) her grandparents next weekend.
(二)翻译句子(使用"be adj. to do" 结构,适配中考书面表达)
我很高兴能参加这次英语演讲比赛。
_____________________________________________________________________.
每天读英语报纸对我们来说很重要。
_____________________________________________________________________.
这款新手机操作起来很简单。
_____________________________________________________________________.
他愿意帮助任何有困难的人。
_____________________________________________________________________.
今天下午可能会下大雨。
_____________________________________________________________________.
孩子们渴望在周末去公园玩。
_____________________________________________________________________.
按时完成作业对学生来说是必要的。
_____________________________________________________________________.
她害怕在众人面前说话。
_____________________________________________________________________.
这本小说读起来很有趣。
_____________________________________________________________________.
我们准备好迎接即将到来的中考了。
_____________________________________________________________________.
五、提升强化训练(中考高频题型)
(一)单项选择题(中考易错点聚焦)
It is ________ for us to finish the work in such a short time. We need more time.
A. possible B. impossible C. easy D. interesting
She is ________ to hear the good news and she can't help crying.
A. excited B. exciting C. sad D. pleasing
This math problem is too difficult ________. Can you help me
A. solve B. to solve C. solving D. to be solved
It is important ________ us ________ English well.
A. for; to learn B. to; to learn C. for; learn D. to; learn
He is ________ to come to the party because he has to look after his sister.
A. likely B. unlikely C. able D. willing
— I'm sorry ________ your cup. — It doesn't matter.
A. break B. breaking C. to break D. broke
She is willing ________ me with my homework every evening.
A. help B. to help C. helping D. helps
It is ________ to walk in the rain with an umbrella.
A. nice B. sad C. afraid D. able
He ________ speak French when he was young, but now he can't.
A. is able to B. was able to C. can D. could to
— How do you like this book — It is ________ to read. I want to read it again.
A. bored B. boring C. interested D. interesting
(二)完形填空(节选中考真题改编,围绕核心结构)
Everyone wants to be healthy. It is___1___for us to keep healthy. First, we should eat healthy food every day. Vegetables and fruits are good for our bodies. Second, it is important ___2____exercise every morning. Running and walking are easy___3___ . Third, we are glad___4____enough sleep every night. We should go to bed early and get up early. Finally, we should be willing____5_____ help others. Being happy is also good for our health. If we follow these rules, we will be healthy and strong.
A. necessary B. impossible C. sad D. exciting
A. take B. to take C. taking D. takes
A. do B. doing C. to do D. done
A. have B. to have C. having D. has
A. to B. for C. with D. of
六、参考答案及详细解析
(一)基础巩固练习答案及解析
1. 用所给动词的适当形式填空
to receive 解析:情感驱动类结构(be glad to do),不定式作原因状语,表“高兴做某事的原因”。
to obey 解析:事情属性类结构,it为形式主语,真正主语是不定式to obey...,表“遵守交通规则很重要”。
to operate 解析:事情属性类结构,主语this machine为物,不定式用主动形式表被动,补充说明机器“易操作”的属性。
to donate 解析:特殊句型类(be willing to do),表“愿意做某事”,为固定搭配。
to snow 解析:特殊句型类(be likely to do),表“可能发生某事”,it为形式主语。
to tell 解析:情感驱动类结构(be sorry to do),表“抱歉做某事”,不定式作原因状语。
to read 解析:事情属性类结构,主语this story为物,不定式主动表被动,表“故事读起来有趣”。
to swim 解析:特殊句型类(be able to do),由when he was 10可知用过去时was able to,后接动词原形。
to study 解析:事情属性类结构,It is necessary for sb. to do sth.为固定句式,for us为不定式逻辑主语。
to visit 解析:特殊句型类(be eager to do),表“渴望做某事”,为固定搭配。
2. 翻译句子答案及解析
译文: I am very glad to take part in this English speech contest. 解析:情感驱动类(be glad to do),take part in为固定短语“参加”,适配演讲比赛场景。
译文: It is important for us to read English newspapers every day. 解析:事情属性类,it作形式主语,真正主语为to read...,for us补充逻辑主语,符合中考书面表达习惯。
译文: This new mobile phone is easy to operate. 解析:事情属性类,主语为物,不定式主动表被动,表“手机易操作”。
译文: He is willing to help anyone who is in trouble. 解析:特殊句型类(be willing to do),who is in trouble为定语从句修饰anyone,提升句子复杂度,适配中考作文。
译文: It is likely to rain heavily this afternoon. 解析:特殊句型类(be likely to do),it作形式主语,表“可能下大雨”。
译文: The kids are eager to play in the park on weekends. 解析:特殊句型类(be eager to do),“在周末”译为on weekends,符合中考表达。
译文: It is necessary for students to finish homework on time. 解析:事情属性类,It is necessary for sb. to do sth.,“按时”译为on time。
译文: She is afraid to speak in front of people. 解析:特殊句型类(be afraid to do),“在众人面前”译为in front of people。
译文: This novel is interesting to read. 解析:事情属性类,主语为物,不定式主动表被动,“小说”译为novel(中考课标词汇)。
译文: We are ready to face the coming high school entrance exam. 解析:特殊句型类(be ready to do),“中考”译为high school entrance exam(标准表达)。
(二)提升强化训练答案及解析
1. 单项选择题
B 解析:由“We need more time”可知“短时间内完成工作不可能”,impossible(不可能的)符合语境,中考高频形容词。
A 解析:主语为she(人),用excited(感到兴奋的);exciting修饰物,pleasing表“令人愉快的”,均不符合语境。
B 解析:事情属性类结构,主语为物时,“be difficult to do”用主动形式表被动,无需加be,为中考易错点。
A 解析:固定句式It is important for sb. to do sth.,for后接人(逻辑主语),to后接动词原形,为中考必背句式。
B 解析:由“he has to look after his sister”可知“他不太可能来派对”,unlikely(不太可能的)符合语境;likely表“可能的”,与句意相反。
C 解析:情感驱动类结构be sorry to do sth.,表“抱歉做某事”,不定式作原因状语。
B 解析:特殊句型类be willing to do sth.,为固定搭配,to后接动词原形。
A 解析:结合语境“带伞在雨中散步很惬意”,nice(愉快的)符合;sad(难过的)、afraid(害怕的)、able(能够的)均不符合。
B 解析:由when he was young可知用过去时,be able to的过去时为was/were able to;can的过去时为could,后接动词原形,无could to结构。
D 解析:主语为it(指代book),用interesting(令人有趣的);bored、interested修饰人,boring表“令人无聊的”,不符合句意。
2. 完形填空
A 解析:结合上下文“保持健康对我们来说是必要的”,necessary(必要的)符合语境;impossible(不可能的)、sad(难过的)、exciting(令人兴奋的)均不符合。
B 解析:固定句式It is important to do sth.,it为形式主语,真正主语是不定式to take exercise,to后接动词原形。
C 解析:事情属性类结构,“be easy to do”,主语为Running and walking,不定式用主动形式表被动,译为“跑步和散步是容易做的运动”。
B 解析:情感驱动类结构be glad to do sth.,表“很高兴做某事”,to后接动词原形have,“有足够的睡眠”译为have enough sleep。
A 解析:特殊句型类be willing to do sth.,为固定搭配,to后接动词原形help,表“愿意帮助别人”。
七、中考总结与备考建议
“be adj. to do”结构是中考英语语法的核心考点之一,覆盖单选、完形、填空、翻译及书面表达等多种题型。备考重点需掌握三点:1. 三大结构的核心区别(情感类主语多人、属性类常用it作形式主语、特殊句型为固定搭配);2. 易错点辨析(如excited/exciting、possible的用法、主动表被动等);3. 固定句式的灵活运用(如It is + adj. + for sb. to do sth.)。
建议在复习中结合本讲义的练习,熟练背诵高频形容词及搭配,同时在书面表达中刻意运用该结构,提升句式多样性,助力中考取得优异成绩。
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