作业帮语法点+5个例句 越多越好
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语法点+5个例句 越多越好
40个左右
40个左右
主谓一致关系应遵循三项原则,即：语言意义上一致、语法形式上一致和就近原则.
语言意义上一致：当主语在形式上是单数,意义上是复数时,谓语动词要用复数形式；当主语在形式上是复数而意义上是单数时,谓语动词要用单数形式.
一. 集体名词,如：family,team,class等作主语时,如果作为一个单位（整体）看待,谓语动词用单数形式；如果作为整体中的各个成员看待时,谓语动词用复数形式.如：
一、概念不同：
一般现在时表示主语经常性和习惯性的动作或存在的状态,也表示说话者的能力及自然现象.而现在进行时表示说话时（瞬间）正在进行的动作,也表示目前或现阶段一直进行的动作.如：
She often does her homework in the evening. 她经常在晚上做作业.
She is doing her homework now. 现在她正在做作业.
二、在构成方式上的不同：
一般现在时中谓语动词的构成有以下三种情况：
①be动词的一般现在时形式：am,is,are.
②动词have的一般现在时形式：have,has.
③其他行为动词的一般现在时形式有动词原形或第三人称单数形式.
而现在进行时中谓语动词的构成是：am/is/are+动词的-ing形式（现在分词）.
三、时间状语不同：
一般现在时的时间状语主要有：always,usually,often,sometimes,never,every day,on Sundays,in the morning/afternoon/evening等；
现在进行时的时间状语主要有：now,these days,this week,at the moment等,有时句首有“Look!”、“Listen!”或“It’s+时刻”等词、句存在.如：
We play football in the afternoon.我们在下午踢足球.（一般现在时）
My mother is reading a newspaper now. 我妈妈正在看报纸.（现在进行时）
四、感情色彩不同：
一般现在时往往不带任何感情色彩,语气比较肯定.现在进行时常带有一定的感情色彩,并多与always, often等副词连用.如：
Mr. Li works hard in the factory. 李先生在工厂工作努力.（说明事实,语气比较肯定）
Mr. Li is always working hard in the factory.李先生在工厂工作一直很努力.（表示赞扬）
五、用语范围不同：
某种表示情感、意识（如want,like,know等）；表示“有”的have等动词,一般不用于现在进行时,但可用于一般现在时.如：
我现在就想回家.
误：I am wanting to go home now.
正：I want to go home now.
他有一台电脑.
误：He is having a computer.
正：He has a computer.
六、时间范围不同：
这两种时态所表示的时间范围都可能有“过去——现在——将来”的意味,但相对而言,一般现在时持续的时间较长,甚至无限.而现在进行时持续的时间较短,可能片刻完成.如：
She comes from Shanghai. 她是上海人.
She is coming from Shanghai.她正从（或即将从）上海来
My family is a small one, but my family all like watching football matches.
（前者指“家庭”,后者指“家人”）
二. 表示总称意义的名词,如people,police等作主语时,谓语动词用复数形式.如：
Of all things, people are the most important.
三. “百分数词/分数词 + of + 复数名词”作主语时,谓语动词用复数形式；但“百分数词 / 分数词 + of + 不可数名词/单数可数名词”作主语时,谓语动词要用单数形式.如：
2/3 of the workers are from Japan.
40 percent of my homework has been finished.
四. 表示“金钱、时间、距离、重量”等名词作主语时,谓语动词用单数形式.如：
100 years is not long.
五. all作主语,如果指代人或可数名词含有复数意义时,谓语动词用复数形式；如果指代抽象性事物时,其谓语动词要用单数形式.如：
All are here. 大家都在这儿.
All is going on well. 一切进展顺利.
六. “none of + 不可数名词”作主语时,其谓语动词用单数形式,“none + of 复数代词/ 复数名词”作主语时,谓语动词可用单数形式也可用复数形式.如：
None of the food was wasted.
None of us knows / know how to work out the problem.
七. Chinese, Japanese, deer, sheep等单、复数同形的名词作主语时,它们自身在句中的意义决定其谓语动词的单、复数形式.如：
Chinese is one of the eight subjects we must study at school.（Chinese指语言）
These five Chinese are studying English in London.（Chinese指中国人）
语法形式上一致：是指谓语动词与主语的人称和数保持一致.
一、each,another,the other,either,someone,somebody,everyone,everybody,anyone,anybody,something,anything,nothing,no one等不定代词作主语时,谓语动词要用第三人称单数形式.如：
Someone is asking for you.
二、“each/ every + 单数可数名词”作主语时,谓语动词用单数形式.如：
Each student has an English-Chinese dictionary.
三、非谓语动词（短语）、名词性从句作主语时,谓语动词用单数形式.如：
To learn English well is not easy.
When and where we will hold the meeting is unknown.
四、“one and a half + 复数名词”作主语时,谓语动词用单数形式.如：
One and a half years has passed.
五、and连接的两个单数名词,前面如有each,every,any,no等修饰时,谓语用单数形式.如：
No teacher and no student is reading.
六. both,all,few,several,many等修饰可数名词的复数形式作主语时,谓语动词用复数形式.如：
All his friends have come.
就近原则：是指谓语的单复数形式应跟最靠近谓语动词的那个主语的单复数形式相一致.
一、“there be句型”中.如：
There is a boy and three girls in that room.
There are four deer and one bear in that zoo.
二、由“or,either…or…,neither…nor…,not only…but also…”；连接两个并列主语.如：
Either you or I am going there
“be＋过去分词”这个结构既可能是被动语态,也可能是系表结构.二者形式相同,但意义不一样.被动语态表示动作,句子主语是动作的承受者；系表结构表示主语的特点或所处的状态.我们可以根据以下几点来区别这样的结构到底是被动语态,还是系表结构.
一、根据句中有无by引导的短语
被动语态中主语是动作的承受者,动作的执行者常用by引导的短语来表示.因此,如果句中有“be＋过去分词＋by短语”结构,通常就是被动语态.试比较：
The window was closed by my mother. （被动语态）
The window was closed. （系表结构）
二、根据句子的时态
被动语态有多种时态,可用于一般时、将来时、进行时和完成时.而系表结构只用于一般现在时和一般过去时.像下面几个句子,只能是被动语态,而不可能是系表结构.
New products are being made. 新产品正在制造中.
The book has already been translated into many languages.
这本书已被译成多种语言.
The meeting will be put off. 会议将延期.
三、根据句子状语
若“be＋过去分词”结构是一般现在时或一般过去时,我们可以根据句子的状语来区别是被动语态还是系表结构.
1. “be＋过去分词”结构是一般现在时,且句子中有always, usually, often等频度副词说明动作反复发生,则为被动语态.例如：
The shop is usually opened at eight.
商店通常八点钟开门.
2. 当“be＋过去分词”结构是一般过去时,且句中有表示时间、地点、方式的状语,多为被动语态.例如：
The factory was built in 1980’s.
这家工厂是二十世纪八十年代建的.
四、根据谓语动词
不是所有的过去分词都可以作表语,来表示主语所处的状态.只有一部分可以这样用.常见的能这样用的过去分词有：covered, broken, married等.例如：
The glass is broken. 那个杯子坏了.
She got married. 她结婚了
▲引导状语从句的连接词
1. 引导时间状语从句的连词主要有when, while, as, by the time, before, after, since, till/ until, as soon as等.如：
When I got home, he was having supper.
2. 引导原因状语从句的连词有because, since, as, for等.如：
I missed the train because I got up late.
3. 引导结果状语从句的连词主要有so/ such...that..., so that等.如：
She is so short that she can’t reach the buttons of the lift.
4. 引导让步状语从句的连接词有though, although, even if, even though, however/ no matter how, whatever/ no matter what等.如：
Although it’s raining, they are still working in the field.
5. 引导条件状语从句的连接词有if, unless, as long as等.如：
You won’t pass the exam unless you work hard on it.
▲引导宾语从句的连接词
一般来说,宾语从句的引导词是根据从句的原句句式而定：原句是陈述句时,用引导词that；原句是一般疑问句时,引导词用if或whether；原句是特殊疑问句时,引导词用原疑问词.如：
I am glad（that）you’ve passed the exam.
I don’t know if/ whether it will rain tomorrow.
I wonder where he got so much money.
〔热点二〕对主、从句时态呼应的考查
▲状语从句的时态
以when, as soon as, before, after, until等引导的时间状语从句和if引导的条件状语从句,当主句用一般将来时,从句要用一般将在时表示将来.如：
I’ll tell you as soon as he comes back tomorrow.
▲宾语从句的时态
1. 宾语从句的时态要和主句时态相呼应.当主句谓语动词是过去时态时,宾语从句也要用相应的过去时态（即一般过去时、过去进行时、过去将来时或过去完成时）.如：
Li Lei told me that he was getting ready for the exam these days.
2. 若主句是现在时或将来时,宾语从句可根据情况选用恰当的时态.如：
The radio reports that it’s going to rain this afternoon.
3. 若从句表示自然现象或客观真理时,其时态常用一般现在时,而不受主句限制.如：
Yesterday Tom said that the earth goes round the sun.
〔热点三〕对复合句简化的考查
▲含有状语从句的复合句转化为简单句
so...that...引导的结果状语从句有两种情况：1）表示肯定的结果,可与“enough to”结构互换；2）表示否定的结果,它既可以与“too...to”结构互换,也可以改为“not + adj./ adv. + enough to”.如：
The room is so large that it can hold 1,000 people. →The room is large enough to hold 1,000 people.
▲含有宾语从句的复合句转化为简单句
1. 主句谓语动词为hope, wish, agree, decide, choose等,其后带（that）宾语从句,若主从句主语一致时,从句可以简化成不定式结构.如：
He decides that he will visit our school.→He decides to visit our school.
2. 主句的谓语动词为感官动词see, hear, watch或find等时,宾语从句常简化成“感官动词find＋宾语＋宾语补足语”结构,此时宾语由从句的主语转化而来,而宾语补足语多为不带to的不定式或V-ing形式.如：
I saw that some children were playing in the park.→I saw some children playing in the park.
3. 由特殊疑问词引导的宾语从句,当主从句主语一致时,宾语从句可简化成“疑问词＋不定式”结构.如：
I don’t know how I can get there. →I don’t know how to get there.
〔热点四〕对两类从句综合起来考查
1. 从引导词看,if充当宾语从句的连接词时,相当于whether,意为“是否”；充当从属连词,引导条件状语从句时,意为“如果”.when充当宾语从句的连接词时,意为“什么时候”；充当从属连词,引导时间状语从句时,意为“当……的时候”.
2. 从时态看,if和when作连接词,引导宾语从句时,宾语从句中和谓语动词的时态应根据主句的谓语动词的时态作相应的变化；if和when充当从属连词,引导表示将来动作或状态的条件状语从句或时间状语从句时,若主句中的谓语动词用一般将来时,则从句中的谓语动词通常用一般现在时表示将来.
1. 作主语
作主语的不定式如果很短,通常位于句首,如：To see is to believe.若不定式（短语）较长时,常用it作形式主语,而把真正的主语（即动词不定式）放在后面,以避免头重脚轻.常见句型为：“It”s +名词（for + sb）+ to do sth“和”It“s +形容词（for / of + sb）+ to do sth”.注意：在这个句型结构中,若形容词表示与人有关的“赞美”或“批评”时用of,如kind,nice,good,clever,bad等；否则用for.如：
It“s easy for you to answer the question.
It“s very kind of you to help me.
2. 作表语
动词不定式可以作be,seem,appear等系动词的表语.如：
Her job is to take care of these children.
3. 作状语
动词不定式放在come,go,stop等动词后作目的状语；放在sorry,glad,surprised,pleased,angry等形容词后作原因状语；动词不定式作状语表示结果时常与副词too或enough连用.注意：too…to与so…that…和（not）…enough to…可以相互转换：如：
She is so weak that she can“t move the box.
=She is too weak to move the box.
=She is not strong enough to move the box.
4. 疑问词+不定式
疑问词+不定式=名词短语,可作主语、宾语或表语.注意：名词短语可以由名词从句转换而来；疑问代词what,which,whom可以作宾语,疑问副词how,when,where,whether不能作宾语.如：
I didn“t know what I should do. = I didn”t know wheat to do.
I didn“t know how I should do it. = I didn”t know how to do it.
5. 几种不带to的动词不定式句式
had better…, Why not…? Will / Would you please…?等句型后接不带to的不定式.如：
You had better stay at home.
Why not see a doctor?
现在进行时表示某人正在做某事,它不仅有肯定式、否定式和一般疑问式,还有特殊疑问式.从陈述句变成疑问句可以从以下几个方面进行提问：
「对主语提问」
首先要看清楚句子的主语是表示人的词还是表示事物的词.如果主语是表示人的词,将该主语改为who；如果主语是表示事物的词,则改为what.例如：
①Wang Ping is playing football in the park now.
→Who is playing football in the park now?
②The horse is running fast.
→What is running fast?
「对句子的谓语提问」
现在进行时的谓语由is,am或are加动词的-ing形式构成.对句子的谓语部分进行提问,要使用疑问词 what,然后将原句的谓语动词改为 doing,最后可别忘了将原来的宾语去掉.例如：
Wang Ping is playing football in the park now.
→What is Wang Ping doing in the park now?
「对句子的宾语进行提问」
如果宾语是表示人的词,用whom提问；如果宾语是表示事物的词,用what提问,将whom或what 放在句首.例如：
①Wang Ping is playing football in the park now.
→What is Wang Ping doing in the park now?
②Tom is helping John over there.
→Whom is Tom helping over there?
「对句子的状语进行提问」
首先要弄清楚句子的状语是作什么用的.一般来说,表示时间的状语用when提问；表示地点的状语用where提问；表示做事方式的状语用how提问.例如：
①Wang Ping is playing football in the park now.
→When is Wang Ping playing football in the park?
②Wang Ping is playing football in the park now.
→Where is Wang Ping playing football now?
③They are working hard in the fields.
→How are they working in the fields?
1.先行词表示时间、地点、原因,但关系词指代先行词在定语从句中充当主语或宾语时,应用关系代词that或which.如：
I’ll never forget 1976 that / which was full of sadness.
（作主语）
我不会忘记充满悲哀的1976年.
I regret the days （that/which） I wasted in the woods.
（作宾语）
我后悔在森林里虚度的日子.
This is the factory that/which produces cars. （作主语）
这就是那个生产小汽车的工厂.
This is the factory （that/which） he visited yesterday.
（作宾语）
这就是他昨天参观的工厂.
This is the reason that/which is unreasonable. （作主语）
这是一个没道理的理由.
This is the reason （that/which） he raised. （作宾语）
这是他提出的理由.
2. 关系副词有时相当于 “适当的介词+关系代词”.如：
① where=in/on which
This is the room where / in which he lives.
这就是他住的房间.
I can see the desk where / on which there is a book.
我能看见上面有一本书的那张桌子.
② when= on/in/at which
I still remember the year when/ in which I joined the Party. 我仍然记得入党的那一年.
I still remember the day when/on which I joined the Party. 我仍然记得入党的那一天.
I still remember the date when/at which I joined the Paty. 我仍然记得入党的那个日子.
③ why=for which
This is the reason why / for which he was killed.
这是他被杀害的原因.
3. 当先行词为time表示 “次数”时,常用关系词that或省去关系词,而不用when来引导定语从句.如：
This is the first/last time that I shall give you a lesson.
这是我第一次/最后一次给你们上课.
4. 当point,situation等词作先行词表抽象的地点,其后常由where引导定语从句,where在定语从句中作地点状语.
Can you think out a situation where this word can be used? 你能设想这个单词被使用的场合吗?
Her illness has developed to the point where nobody can cure her. 她的病发展到没人能治的地步
语言意义上一致：当主语在形式上是单数,意义上是复数时,谓语动词要用复数形式；当主语在形式上是复数而意义上是单数时,谓语动词要用单数形式.
一. 集体名词,如：family,team,class等作主语时,如果作为一个单位（整体）看待,谓语动词用单数形式；如果作为整体中的各个成员看待时,谓语动词用复数形式.如：
一、概念不同：
一般现在时表示主语经常性和习惯性的动作或存在的状态,也表示说话者的能力及自然现象.而现在进行时表示说话时（瞬间）正在进行的动作,也表示目前或现阶段一直进行的动作.如：
She often does her homework in the evening. 她经常在晚上做作业.
She is doing her homework now. 现在她正在做作业.
二、在构成方式上的不同：
一般现在时中谓语动词的构成有以下三种情况：
①be动词的一般现在时形式：am,is,are.
②动词have的一般现在时形式：have,has.
③其他行为动词的一般现在时形式有动词原形或第三人称单数形式.
而现在进行时中谓语动词的构成是：am/is/are+动词的-ing形式（现在分词）.
三、时间状语不同：
一般现在时的时间状语主要有：always,usually,often,sometimes,never,every day,on Sundays,in the morning/afternoon/evening等；
现在进行时的时间状语主要有：now,these days,this week,at the moment等,有时句首有“Look!”、“Listen!”或“It’s+时刻”等词、句存在.如：
We play football in the afternoon.我们在下午踢足球.（一般现在时）
My mother is reading a newspaper now. 我妈妈正在看报纸.（现在进行时）
四、感情色彩不同：
一般现在时往往不带任何感情色彩,语气比较肯定.现在进行时常带有一定的感情色彩,并多与always, often等副词连用.如：
Mr. Li works hard in the factory. 李先生在工厂工作努力.（说明事实,语气比较肯定）
Mr. Li is always working hard in the factory.李先生在工厂工作一直很努力.（表示赞扬）
五、用语范围不同：
某种表示情感、意识（如want,like,know等）；表示“有”的have等动词,一般不用于现在进行时,但可用于一般现在时.如：
我现在就想回家.
误：I am wanting to go home now.
正：I want to go home now.
他有一台电脑.
误：He is having a computer.
正：He has a computer.
六、时间范围不同：
这两种时态所表示的时间范围都可能有“过去——现在——将来”的意味,但相对而言,一般现在时持续的时间较长,甚至无限.而现在进行时持续的时间较短,可能片刻完成.如：
She comes from Shanghai. 她是上海人.
She is coming from Shanghai.她正从（或即将从）上海来
My family is a small one, but my family all like watching football matches.
（前者指“家庭”,后者指“家人”）
二. 表示总称意义的名词,如people,police等作主语时,谓语动词用复数形式.如：
Of all things, people are the most important.
三. “百分数词/分数词 + of + 复数名词”作主语时,谓语动词用复数形式；但“百分数词 / 分数词 + of + 不可数名词/单数可数名词”作主语时,谓语动词要用单数形式.如：
2/3 of the workers are from Japan.
40 percent of my homework has been finished.
四. 表示“金钱、时间、距离、重量”等名词作主语时,谓语动词用单数形式.如：
100 years is not long.
五. all作主语,如果指代人或可数名词含有复数意义时,谓语动词用复数形式；如果指代抽象性事物时,其谓语动词要用单数形式.如：
All are here. 大家都在这儿.
All is going on well. 一切进展顺利.
六. “none of + 不可数名词”作主语时,其谓语动词用单数形式,“none + of 复数代词/ 复数名词”作主语时,谓语动词可用单数形式也可用复数形式.如：
None of the food was wasted.
None of us knows / know how to work out the problem.
七. Chinese, Japanese, deer, sheep等单、复数同形的名词作主语时,它们自身在句中的意义决定其谓语动词的单、复数形式.如：
Chinese is one of the eight subjects we must study at school.（Chinese指语言）
These five Chinese are studying English in London.（Chinese指中国人）
语法形式上一致：是指谓语动词与主语的人称和数保持一致.
一、each,another,the other,either,someone,somebody,everyone,everybody,anyone,anybody,something,anything,nothing,no one等不定代词作主语时,谓语动词要用第三人称单数形式.如：
Someone is asking for you.
二、“each/ every + 单数可数名词”作主语时,谓语动词用单数形式.如：
Each student has an English-Chinese dictionary.
三、非谓语动词（短语）、名词性从句作主语时,谓语动词用单数形式.如：
To learn English well is not easy.
When and where we will hold the meeting is unknown.
四、“one and a half + 复数名词”作主语时,谓语动词用单数形式.如：
One and a half years has passed.
五、and连接的两个单数名词,前面如有each,every,any,no等修饰时,谓语用单数形式.如：
No teacher and no student is reading.
六. both,all,few,several,many等修饰可数名词的复数形式作主语时,谓语动词用复数形式.如：
All his friends have come.
就近原则：是指谓语的单复数形式应跟最靠近谓语动词的那个主语的单复数形式相一致.
一、“there be句型”中.如：
There is a boy and three girls in that room.
There are four deer and one bear in that zoo.
二、由“or,either…or…,neither…nor…,not only…but also…”；连接两个并列主语.如：
Either you or I am going there
“be＋过去分词”这个结构既可能是被动语态,也可能是系表结构.二者形式相同,但意义不一样.被动语态表示动作,句子主语是动作的承受者；系表结构表示主语的特点或所处的状态.我们可以根据以下几点来区别这样的结构到底是被动语态,还是系表结构.
一、根据句中有无by引导的短语
被动语态中主语是动作的承受者,动作的执行者常用by引导的短语来表示.因此,如果句中有“be＋过去分词＋by短语”结构,通常就是被动语态.试比较：
The window was closed by my mother. （被动语态）
The window was closed. （系表结构）
二、根据句子的时态
被动语态有多种时态,可用于一般时、将来时、进行时和完成时.而系表结构只用于一般现在时和一般过去时.像下面几个句子,只能是被动语态,而不可能是系表结构.
New products are being made. 新产品正在制造中.
The book has already been translated into many languages.
这本书已被译成多种语言.
The meeting will be put off. 会议将延期.
三、根据句子状语
若“be＋过去分词”结构是一般现在时或一般过去时,我们可以根据句子的状语来区别是被动语态还是系表结构.
1. “be＋过去分词”结构是一般现在时,且句子中有always, usually, often等频度副词说明动作反复发生,则为被动语态.例如：
The shop is usually opened at eight.
商店通常八点钟开门.
2. 当“be＋过去分词”结构是一般过去时,且句中有表示时间、地点、方式的状语,多为被动语态.例如：
The factory was built in 1980’s.
这家工厂是二十世纪八十年代建的.
四、根据谓语动词
不是所有的过去分词都可以作表语,来表示主语所处的状态.只有一部分可以这样用.常见的能这样用的过去分词有：covered, broken, married等.例如：
The glass is broken. 那个杯子坏了.
She got married. 她结婚了
▲引导状语从句的连接词
1. 引导时间状语从句的连词主要有when, while, as, by the time, before, after, since, till/ until, as soon as等.如：
When I got home, he was having supper.
2. 引导原因状语从句的连词有because, since, as, for等.如：
I missed the train because I got up late.
3. 引导结果状语从句的连词主要有so/ such...that..., so that等.如：
She is so short that she can’t reach the buttons of the lift.
4. 引导让步状语从句的连接词有though, although, even if, even though, however/ no matter how, whatever/ no matter what等.如：
Although it’s raining, they are still working in the field.
5. 引导条件状语从句的连接词有if, unless, as long as等.如：
You won’t pass the exam unless you work hard on it.
▲引导宾语从句的连接词
一般来说,宾语从句的引导词是根据从句的原句句式而定：原句是陈述句时,用引导词that；原句是一般疑问句时,引导词用if或whether；原句是特殊疑问句时,引导词用原疑问词.如：
I am glad（that）you’ve passed the exam.
I don’t know if/ whether it will rain tomorrow.
I wonder where he got so much money.
〔热点二〕对主、从句时态呼应的考查
▲状语从句的时态
以when, as soon as, before, after, until等引导的时间状语从句和if引导的条件状语从句,当主句用一般将来时,从句要用一般将在时表示将来.如：
I’ll tell you as soon as he comes back tomorrow.
▲宾语从句的时态
1. 宾语从句的时态要和主句时态相呼应.当主句谓语动词是过去时态时,宾语从句也要用相应的过去时态（即一般过去时、过去进行时、过去将来时或过去完成时）.如：
Li Lei told me that he was getting ready for the exam these days.
2. 若主句是现在时或将来时,宾语从句可根据情况选用恰当的时态.如：
The radio reports that it’s going to rain this afternoon.
3. 若从句表示自然现象或客观真理时,其时态常用一般现在时,而不受主句限制.如：
Yesterday Tom said that the earth goes round the sun.
〔热点三〕对复合句简化的考查
▲含有状语从句的复合句转化为简单句
so...that...引导的结果状语从句有两种情况：1）表示肯定的结果,可与“enough to”结构互换；2）表示否定的结果,它既可以与“too...to”结构互换,也可以改为“not + adj./ adv. + enough to”.如：
The room is so large that it can hold 1,000 people. →The room is large enough to hold 1,000 people.
▲含有宾语从句的复合句转化为简单句
1. 主句谓语动词为hope, wish, agree, decide, choose等,其后带（that）宾语从句,若主从句主语一致时,从句可以简化成不定式结构.如：
He decides that he will visit our school.→He decides to visit our school.
2. 主句的谓语动词为感官动词see, hear, watch或find等时,宾语从句常简化成“感官动词find＋宾语＋宾语补足语”结构,此时宾语由从句的主语转化而来,而宾语补足语多为不带to的不定式或V-ing形式.如：
I saw that some children were playing in the park.→I saw some children playing in the park.
3. 由特殊疑问词引导的宾语从句,当主从句主语一致时,宾语从句可简化成“疑问词＋不定式”结构.如：
I don’t know how I can get there. →I don’t know how to get there.
〔热点四〕对两类从句综合起来考查
1. 从引导词看,if充当宾语从句的连接词时,相当于whether,意为“是否”；充当从属连词,引导条件状语从句时,意为“如果”.when充当宾语从句的连接词时,意为“什么时候”；充当从属连词,引导时间状语从句时,意为“当……的时候”.
2. 从时态看,if和when作连接词,引导宾语从句时,宾语从句中和谓语动词的时态应根据主句的谓语动词的时态作相应的变化；if和when充当从属连词,引导表示将来动作或状态的条件状语从句或时间状语从句时,若主句中的谓语动词用一般将来时,则从句中的谓语动词通常用一般现在时表示将来.
1. 作主语
作主语的不定式如果很短,通常位于句首,如：To see is to believe.若不定式（短语）较长时,常用it作形式主语,而把真正的主语（即动词不定式）放在后面,以避免头重脚轻.常见句型为：“It”s +名词（for + sb）+ to do sth“和”It“s +形容词（for / of + sb）+ to do sth”.注意：在这个句型结构中,若形容词表示与人有关的“赞美”或“批评”时用of,如kind,nice,good,clever,bad等；否则用for.如：
It“s easy for you to answer the question.
It“s very kind of you to help me.
2. 作表语
动词不定式可以作be,seem,appear等系动词的表语.如：
Her job is to take care of these children.
3. 作状语
动词不定式放在come,go,stop等动词后作目的状语；放在sorry,glad,surprised,pleased,angry等形容词后作原因状语；动词不定式作状语表示结果时常与副词too或enough连用.注意：too…to与so…that…和（not）…enough to…可以相互转换：如：
She is so weak that she can“t move the box.
=She is too weak to move the box.
=She is not strong enough to move the box.
4. 疑问词+不定式
疑问词+不定式=名词短语,可作主语、宾语或表语.注意：名词短语可以由名词从句转换而来；疑问代词what,which,whom可以作宾语,疑问副词how,when,where,whether不能作宾语.如：
I didn“t know what I should do. = I didn”t know wheat to do.
I didn“t know how I should do it. = I didn”t know how to do it.
5. 几种不带to的动词不定式句式
had better…, Why not…? Will / Would you please…?等句型后接不带to的不定式.如：
You had better stay at home.
Why not see a doctor?
现在进行时表示某人正在做某事,它不仅有肯定式、否定式和一般疑问式,还有特殊疑问式.从陈述句变成疑问句可以从以下几个方面进行提问：
「对主语提问」
首先要看清楚句子的主语是表示人的词还是表示事物的词.如果主语是表示人的词,将该主语改为who；如果主语是表示事物的词,则改为what.例如：
①Wang Ping is playing football in the park now.
→Who is playing football in the park now?
②The horse is running fast.
→What is running fast?
「对句子的谓语提问」
现在进行时的谓语由is,am或are加动词的-ing形式构成.对句子的谓语部分进行提问,要使用疑问词 what,然后将原句的谓语动词改为 doing,最后可别忘了将原来的宾语去掉.例如：
Wang Ping is playing football in the park now.
→What is Wang Ping doing in the park now?
「对句子的宾语进行提问」
如果宾语是表示人的词,用whom提问；如果宾语是表示事物的词,用what提问,将whom或what 放在句首.例如：
①Wang Ping is playing football in the park now.
→What is Wang Ping doing in the park now?
②Tom is helping John over there.
→Whom is Tom helping over there?
「对句子的状语进行提问」
首先要弄清楚句子的状语是作什么用的.一般来说,表示时间的状语用when提问；表示地点的状语用where提问；表示做事方式的状语用how提问.例如：
①Wang Ping is playing football in the park now.
→When is Wang Ping playing football in the park?
②Wang Ping is playing football in the park now.
→Where is Wang Ping playing football now?
③They are working hard in the fields.
→How are they working in the fields?
1.先行词表示时间、地点、原因,但关系词指代先行词在定语从句中充当主语或宾语时,应用关系代词that或which.如：
I’ll never forget 1976 that / which was full of sadness.
（作主语）
我不会忘记充满悲哀的1976年.
I regret the days （that/which） I wasted in the woods.
（作宾语）
我后悔在森林里虚度的日子.
This is the factory that/which produces cars. （作主语）
这就是那个生产小汽车的工厂.
This is the factory （that/which） he visited yesterday.
（作宾语）
这就是他昨天参观的工厂.
This is the reason that/which is unreasonable. （作主语）
这是一个没道理的理由.
This is the reason （that/which） he raised. （作宾语）
这是他提出的理由.
2. 关系副词有时相当于 “适当的介词+关系代词”.如：
① where=in/on which
This is the room where / in which he lives.
这就是他住的房间.
I can see the desk where / on which there is a book.
我能看见上面有一本书的那张桌子.
② when= on/in/at which
I still remember the year when/ in which I joined the Party. 我仍然记得入党的那一年.
I still remember the day when/on which I joined the Party. 我仍然记得入党的那一天.
I still remember the date when/at which I joined the Paty. 我仍然记得入党的那个日子.
③ why=for which
This is the reason why / for which he was killed.
这是他被杀害的原因.
3. 当先行词为time表示 “次数”时,常用关系词that或省去关系词,而不用when来引导定语从句.如：
This is the first/last time that I shall give you a lesson.
这是我第一次/最后一次给你们上课.
4. 当point,situation等词作先行词表抽象的地点,其后常由where引导定语从句,where在定语从句中作地点状语.
Can you think out a situation where this word can be used? 你能设想这个单词被使用的场合吗?
Her illness has developed to the point where nobody can cure her. 她的病发展到没人能治的地步