高三英语语法知识点1
一、不定式做主语：
1、不定式做主语一般表示具体的某次动作。===动名词doing 表示习惯的，经常的动作。
e.g: To finish the building in a month is difficult.
To do such things is foolish.
To see is to believe. (对等)
注: 1). 不定式作主语时,谓语用单数
2). 当主语较长，谓语较短时，常用it做形式主语，而将不定式放到谓语的后面。
it做形式主语，不定式放在谓语动词之后常用于下列结构中：
(1)It is/was +adj.+of sb. to do…
(2) It is +adj.+for sb.+to do…
It is easy / difficult / hard / foolish / unwise / right / wrong / unnecessary
(3) it is +a +名词+ to do...
It is a pity / a pleasure / a pleasant thing / one’s duty / an honor / a shame / a crime / no easy job… to do
It takes (sb.) some time / courage / patience …to do…
It requires courage / patience / hard work… to do…
注意: probable 和 possible 均可作表语，但possible可以用不定式作真实主语， 而probable不能用不定式作真实主语。
It is probable for him to come to the meeting.(错)
It is possible for him to come to the meeting.
It is possible / probable that he will come to the meeting.
高三英语语法知识点2
一、非谓语动词
“非谓语动词”可分为动词不定式、动名词和分词.它在句子中的作用很多：除了不作谓语外,它可以充当主语、宾语、表语、定语、状语与复合宾语(主语补语或宾语补语).有些及物动词后面接不带to的不定式作复合宾语.这些动词归纳如下：一感(feel).二听(hear,listen to),三让(have,1et, make),四看(see,watCh,notice,observe).再加上help somebody(to)do something和美国英语look at somebody do somthing.还有“二让”属特殊：get somebody to do something 与keep somebody doing.而有些及物动词后面接动名词(the -ing form)作宾语.这些动词归纳为一句话：Papa C makes friends.这是由如下动词的开头字母组成：permit,advise, practise,avoid,consider,mind, allow,keep,enjoy,suggest, finish,risk,imagine,escape,need,delay,stand(忍受). 为了容易记住,也可以编成顺口溜：“允许完成练习,建议避免冒险,考虑延期逃跑,喜欢保持想象,需要反对忍受”.其相对应的动词依次是：permit/allow,finish,practise;
advise/suggest, avoid,risk： consider, delay, escape/miss; enjoy/appreciate, keep, imagine; need/want/require,mind. can't help/can’t stand.
二、复合句
1、学生最容易混淆的是定语从句与同位语从句的区别.
例如：A、The news that our team has won the match is true. (同位语从句)
B、The news that he told us surprised everybody here. (定语从句)
关键的区别在于连接或关系代词that：有意义的是定语, 无意义的是同位.因为引导定语从句的that在从句中作主语或 宾语,而引导同位语从句的that只起到连接词的作用.
2、接着容易混淆的是引导定语从句的关系代词that与 which：that之前是不定(代词)、序数(词)、(形容词)级：which之前是介词短语与逗号(非限制性).
例如：A、All that we have to do is to practise every day.
B、The first lesson that I learned will never be forgotten.
C、I have lost my pen,which I like very much.
D、The house in front of which there is a garden is my home.
三、It的用法
1、It除了代替人和物以外,还可以作形式主语.而真正的主语(不定式、动名词或从句)则放于谓语或表语之后.
例如：It is nor easy to finish the work in two days.
然而有少数表语之后接动名词作真正的主语.这些表语是：无助(no help)、无用(no use)、没好处(no good);工作(hard work)、费时(a waste of time)、又危险(a danger).
例如：A、It is no use crying over spilt milk.
B、It is a waste of time waiting for him.
2、It还可以作形式宾语.通常下列动词后面可接it作形式宾语：2f2tcjm(find,feel,think,take,consider,judge, make).
例如：A、He made it clear that he was not interested in this subject.
B、I think it no use arguing with him.
3、It用于强调句式.要强调句子的某一部分(主语、宾语、 状语),可以把it当作先行词.这种句子的结构是：It is(was)+ 被强调部分+that(who)+句子的其余部分.
例如：A、It iS Professor Lin who teaches us English—(强调主语)
B、It was in Shanghai that l saw the film.—(强调状语)
C、It was in 1990 that I worked in the factory.(同上)
但要注意与定语从句的区别.
例如：D、It was 1990 when I worked in the factory.(定语从句)
在强调句式里,我们把强调结构It is(was)…that除去,句子还很完整.如例句C.而例句D就不能.
四、倒装结构
学生容易混淆的是全部倒装与部分倒装.如何区分之,编个顺口溜：副(adv.)介(prep.)提前全倒装,其它句式部分倒;否定提前倒助动,让步状语倒表语;复合句式倒主句,不
倒装的属特殊.下面举例说明：
A、Here comes the bus.(副词提前,全倒装)
B、Here he comes.(代词作主语,不倒装)
C、In front of the house lies a garden.(介词短语提前,全倒装)
D、Never shall I do this again.(否定词提前,部分倒装)
E、Young as he is ,he knows a lot.(让步状语从句,表语倒装)
F、Only when he told me did I realize what trouble he was in.(only 修饰状语,主句倒装)
G、Only he can save the patient.(only修饰主语.不倒装)
H、Not only will help be given to people,but also medical treatment will be provided.(否定词提前,部分倒装)
I、Not only he but also we like sports.(连接两个主语,不倒装)
五、虚拟语气
虚拟语气也是一个难点.所谓虚拟语气是表示说话人的愿望、假设、猜测或建议,而不表示客观存在的事实.它通过句子的谓语动词的特殊形式来表示.现归纳如下：纯假设,用虚拟,动词时态退一级：条件句,分主从,主句谓语前加would (should,could,might);表愿望,用虚拟,wish后面接宾语(从句)：现在过去与将来,动词时态退一级：提建议,用虚拟,宾语(从句)动词用(should)do：俩建议,三要求,再加坚持与命令(suggest,advise,demand,require,request,insist,order)：It is time和eoukd rather,后接丛句用虚拟：部分主语从句中, 谓语用虚拟结构 (It is necessry /important/natural/natural/strange/strange that……should do). 下面举例说明：
A、If you came tomorrow,we would have the metting. (条件句虚拟)
B、Without air,there would be no living things.(同上)
C、We wish we had arrived there two hours earlier.(表示愿望虚拟)
D、He demanded that we (should)start right away.(表示建议虚拟)
E、It is(high)time that we left (should leave)now.(特殊从句虚拟)
F、I would rather you gave me the book.(同上)
G、It is necessary that we should clean the room everyday,(主语从句虚拟)
H、He speaks English so fluently as if he were English. (特殊从句虚拟)
高三英语语法知识点3
宾语从句就是在复合句中作宾语的名词性从句，通常放在主句谓语动词 (及物动词) 或介词之后。
1. 作动词的宾语
(1) 由that引导的宾语从句(that 通常可以省略)， 例如：
I heard that be joined the army. 我听说他参军了。
(2) 由what, whether (if) 引导的宾语从句，例如：
a) She did not know what had happened. 她不知道发生了什么。
b) I wonder whether you can change this note for me. 我想知道你是否能帮我改一下笔记。
(3) 动词+间接宾语+宾语从句。例如：
She told me that she would accept my invitation. 她对我说她会接受我的邀请。
2. 作介词的宾语，例如：
Our success depends upon how well we can cooperate with one another. 我们的成功取决于我们之间的合作。
3. 作形容词的宾语，例如：
I am afraid (that) I've made a mistake. 我恐怕我已经犯了一个错误。
注意：that 引导的从句常跟在下列形容词后作宾语：anxious, aware, certain, confident, convinced, determined, glad, proud, surprised, worried, sorry, thankful, ashamed, disappointed, annoyed, pleased, hurt, satisfied, content 等。也可以将此类词后的that 从句的看作原因状语从句。
4. it 可以作为形式宾语
it 不仅可以作为形式主语，还可以作为形式宾语而真正的宾语that 从句则放在句尾，特别是在带复合宾语的句子中。 例如：
We heard it that she would get married next month. 我听说她下个朋就会结婚了。
5. 后边不能直接跟that 从句的动词
这类动词有allow, refuse, let, like, cause, force, admire, condemn, celebrate, dislike, love, help, take, forgive等。这类词后可以用不定式或动名词作宾语，但不可以用that引导的宾语从句。如：
正确表达：I admire their winning the match.
错误表达：I admire that they won the match.
6. 不可用that从句作直接宾语的动词
有些动词不可用于“动词+间接宾语+that从句”结构中，常见的有envy, order, accuse, refuse, impress, forgive, blame, denounce, advise, congratulate等。例如：
正确表达：He impressed the manager as an honest man.
错误表达：He impressed the manager that he was an honest man.
7. 否定的转移
若主句谓语动词为think, consider, suppose, believe, expect, fancy, guess, imagine等，其后的宾语从句若含有否定意义，一般要把否定词转移到主句谓语上，从句谓语用肯定式。例如：
I don't think this dress fits you well. 我认为这件衣服不适合你穿。
表语从句
表语从句在复合句中作表语的名词性从句，放在系动词之后，一般结构是“主语+连系动词+表语从句”。可以接表语从句的连系动词有be, look, remain, seem等。引导表语从句的that常可省略。另外，常用的还有the reason is that… 和It is because 等结构。例如：
1) The question is whether we can make good preparation in such a short time.
2) This is why we can't get the support of the people.
3) But the fact remains that we are behind the other classes.
4) The reason he is late for school is that he missed the early bus.
同位语从句
同位语从句就是在复合句中作名词的同位语的名词性从句。
1. 同位语从句的功能
同位语从句对于名词进一步解释，说明名词的具体内容，一般由that引导，例如：
1) The king's decision that the prisoner would be set free surprised all the people.
2) The order that all the soldiers should stay still is given by the general.
2. 同位语在句子中的位置
同位语从句有时可以不紧跟在它所说明的名词后面，而是被别的词隔开。例如：
He got the news from Mary that the sports meeting was put off.
3. 同位语从句与定语从句的区别
(1) 定语从句中的that既代替先行词，同时以在从句中作某个成分(主语或宾语)，而同位语从句中的that是连词，只起连接主句与从句的作用，不充当句中任何成分。
(2) 定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述定的性质或特征;同位语从句是名词性的，其功能是对名词进行补充说明。例如：
1) The news that he told me is that Tom would go abroad next year.(他告诉我的消息是汤姆明年将出国。)(第一个that引导的从句是定语从句，that在从句中作宾语)
2)The news that Tom would go abroad is told by him.(汤姆将出国的消息是他讲的。)(同位语从句，that在句中不作任何成分)