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教案能够帮助教师提前预测学生可能遇到的问题，并做好解决方案。编写和使用教案对于教师的教学工作具有重要意义。下面是小编为大家整理的高中英语必修三教案，如果大家喜欢可以分享给身边的朋友。
高中英语必修三教案 【篇1】
重点句型
1. We usually think of science subjects asphysics, chemistry, biology and mathematics.
通常我们认为科学学科为物理、化学、生物、和数学。
2. When are they to hand in their plan?
他们的计划什么时候交上来。
3. Whether we help him or not, he will fail.
不论我们帮助他与否，他都将失败。
4. It exploded loudly with fire and rock, whichwere in time to produce the water vapour, carbon dioxide, oxygen, nitrogen andother gases, which were to make the earth’s atmosphere.
它(地球)巨大的爆炸喷出了烈火与岩石，最终产生了水蒸气、二氧化碳、氧、氮和其他多种气体，从而形成了地球的大气层。
5. It was quite different from what I expected.
它和我原来想的很不一样。
6. This made it possible for us to learn English better.
这使得我们有可能把英语学得更好。
7. Scientist believe that taking carbon dioxide from the atmosphere and filling the air with oxygen helped life to develop.
科学家认为，从大气中吸取二氧化碳，并向空气中释放氧气，有助于生命的发展。
8. He has experience as well as knowledge.
他既有学识又有经验。
9. They are putting too much carbon dioxide into the atmosphere ,which prevents heat from escaping from the earth intospace.
他们把太多的二氧化碳释放到大气层中，这使得热量不能从地球上散发到太空中。
10. Whether life will continute on the earth formillions of years will depend on whether this problem can be solved.
生命是否会在地球上延续几百万年要取决于这个问题能否得到解决。
11. Canada is the second largest country in the world.
加拿大是世界上第二大的国家。
12. Success is within our grasp now.
现在我们成功在望了。
13. I’m feeling slightly better today.
我今天感到好一点了。
14. I prefer to play football rather than stayat home.
我宁愿踢足球而不愿呆在家里。
15. He gave me money as well as advice.(as well as 和;同;也)
他给我忠告并且给我钱。
16. These books are mine; the rest are yours.
这些书是我的，其他的都是你的。
17.I asked her a question but she remainedsilent.(remaine 是连系动词，意思是“保持，仍然是”)
我问了她一个问题，但她保持沉默。
18. Many people think it is the most beautifulcity in Canada, as it is surrounded by mountains on the north and east and thePacific Ocean on the west.
许多人都认为温哥华是加拿大最美丽的城市，因为来自它的北面和东面都被大山包围，而西面濒临太平洋。
19. Many of them have a gift for working withanimals and they can win thousands of dollars in prizes.
他们中的许多人拥有与兽共舞的天分，因而能赢得数千美元的奖金。
20. You can have a view of Paris from the EiffelTower.
从埃菲尔铁塔上你可以看到巴黎全景。
21. Around noon they arrived in Toronto, the mostwealthy and biggest city in Canada.
大约中午时分她们到了多伦多—加拿大最富有、最大的城市。
22. I accompanied him as far as the bus stop.
我陪他一直走到公共汽车站。
高中英语必修三教案 【篇2】
Ⅰ. 常考单词必背
1.scenery n. 景色;风景
Sometimes they just drive slowly down the lane enjoying the scenery.
有时他们只是沿着小路慢慢地开车，欣赏两旁的风景。
2. surround vt. &vi. 包围;围绕
Jill was sitting on the floor surrounded by boxes.
吉尔坐在地板上，周围摆满了箱子。
[快速闪记]
(1)be surrounded by/with... 周围环绕着……;被……包围
surround oneself with 和……在一起;与……为伍
(2)surrounding adj. (作定语)周围的;附近的
surroundings n. 周围的事物(或情况);环境
3. measure vi. &vt. 测量;衡量;判定 n. 计量制;计量单位;措施
The government has taken measures to help the unemployed to find jobs again.
政府已经采取措施来帮助失业者重新就业。
[快速闪记]
take measures to do sth 采取措施做某事
take one's measure 量某人的尺寸
to one's measure 按照某人的尺寸
4.aboard prep.&adv. 在船、飞机、火车或公共汽车上
All the passengers have gone aboard the plane.
所有的乘客都已登机了。
The man with broad shoulders boarded the plane to travel abroad and he only took daily necessaries aboard.
这位肩膀宽阔的人登机去国外旅游，他只携带日常用品上飞机。
[快速闪记]
go aboard 上船/飞机/火车
5.within prep. 在……之内
Do what's within your power!
尽力而为!
[快速闪记]
within one's reach 触手可及
within one's power 力所能及
within the limit of 在……范围内
6. mix vt.&vi. 混合;调配
I always mix him up with his brother.They look so much alike.
我总是把他和他的弟弟弄混了。他们长得太像了。
[快速闪记]
(1)mix...with... 把……与……混合起来
mix up 弄乱;弄错;使……充分混合
be/get mixed up with... 与……交往;与……厮混
(2)mixed adj. 混合的
mixture n. 混合(物);混合状态
7. confirm vt. 证实;证明;批准
It has been confirmed that the singer will give a performance next week.
已经确定这位歌唱家下周演出。
[快速闪记]
confirm sb in sth 使某人确信某事
confirm sth/that... 证实;进一步确定……
It has been confirmed that... 已经确定……
8.terrify vt. 使恐怖;恐吓
The dog rushing out from the house terrified me.
从屋里窜出的那条狗把我吓了一跳。
[快速闪记]
(1)terrify sb into doing sth 威胁某人干某事
be terrified of 害怕
(2)terrifying adj. 可怕的;令人恐怖的
terrified adj. 恐惧的;受惊吓的
9.pleased adj. 欣喜的;高兴的;愉快的
We are very pleased with her decision.
我们对她的决定很满意。
[快速闪记]
修饰人，说明被修饰者的心理感受时，常用下列词的-ed形式：excite，move，tire，bore，frighten，surprise，astonish，shock，annoy，worry，please，satisfy，disappoint，puzzle，interest等。
10. impress vt. 使印象深刻;使铭记
We were deeply impressed with the beauty of the West Lake.
西湖的美给我们留下了深刻的印象。
[快速闪记]
(1)impress sb with sth = impress sth on sb 给某人留下……印象
be impressed by/at/with sth 对……印象深刻
be impressed on sb/one's mind/memory 使某人印象深刻
(2)impression n. 印象
impressive adj. 给人深刻印象的;感人的
Ⅱ. 高频短语必会
1. settle down 定居;平静下来;专心于
I must settle down this morning and finish the term paper.
我今天上午必须安下心来完成学期论文。
[快速闪记]
settle down to (doing) sth 开始认真对待某事物;定下心来做某事
2. manage to do 设法做
He managed to get a few tickets for the Olympic Games.
他设法弄到了几张奥运会的门票。
3. catch sight of 看见;瞥见
Catching sight of his headteacher，the boy ran away.
看到班主任后，那个男孩跑开了。
[快速闪记]
lose sight of 看不见，消失
out of sight 看不见
within/in sight 在视野内，看得见
4. have a gift for 对……有天赋
He has a gift for painting.
他有绘画方面的天分。
[快速闪记]
be gifted in/at 在……方面有天赋
have a talent/genius for 有……禀赋;有……方面的才能
5. in the distance 在远处
We heard gunfire in the distance.
我们听见了远处的炮声。
[快速闪记]
from/at a distance 隔一段距离;从远处
at a distance of... 在……远处
keep sb at a distance 避免与某人太亲近
6.as far as 远到……;就……而言
After dinner we often walk as far as the bank of the river.
晚饭后我们常常散步远到那条河边。
[快速闪记]
as far as I know 据我所知
as far as I can remember/see/tell... 据我所能记得的/看到的/判断……
as far as I am concerned 就我而言
高中英语必修三教案 【篇3】
第五单元
1 ) confuse
表示“使糊涂，搞乱，混淆”。
confuse A and/with B 把 A 误认为是 B 。
形容词 confused 表示“糊涂的，混杂的”。
2 ) coast
表示“海岸，滑坡”。
the coast in clear 是一习惯用语，表示“没有被发现或者被捉住的危险”。
3 ) settle down
表示“定居，平静下来，专心于，舒适地躺着或者坐着”。
有关 settle 的词组：
settle on sth 决定做某事 settle sth on sb 将……转让给某人 settle for sth 勉强认可某事 settle one ’ s/an account ( with sb )为受到的伤害，侮辱等，复仇。
4 ) have a gift for
表示“对……有天赋”。
形容词 gifted 表示“有天赋的”。 be gifted at/in 表示“对……有天赋”。
gift 也可表示“礼物”。
5 ) border
作及物动词，表示“与……接壤，给……镶边”。
作不及物动词，后接介词 on 或 upon ，表示“邻近，接界，近似，近乎”。
作名词，表示“边界，国界”。指具体的边界线或边界线内的一带地方。
还表示“在……的边缘，正要，将要”。
6 ) official
official “官员，职员，公务员”通常指在政府部门工作的文职官员。
official 作形容词，表示“官方的，正式的，公务的”。
7 ) tour
作动词，表示“旅游，观光，巡回”。
作名词，表示“游历，巡行，参观”。
make/take/go on a tour ( of+ 地点名词)表示“在(某地)进行旅行”。
on tour 在巡回中。
8 ) distance
表示“距离”，也可以指长时间的久远。
in the distance 在远处。
from a distance 从远处。
keep sb at a distance 对某人疏远，冷淡地对待某人。
9 ) flow
作名词，表示“流程，流量，涨潮”。
作动词，表示“流动，畅通无阻，(讲话或写作)流畅”。
flow in/into 不断涌入。
10 ) as far as
表示“远到，直到，就……而言”，也可用 so far as 。
有关 far 的词组：
by far 很，甚，极 far and away 远远，远远超过 far and near 远近，到处 far and wide 广泛，到处普遍 far away 遥远的 far from 远非，决不，完全不 so far as 到……程度，远到，就……而论 go too far 做得太过分
11 ) speed
作动词，表示“迅速前进，快行”。
speed up (使)加快，(使)加速，其过去式和过去分词多用 speeded 。
作名词，表示“速度，速率”时是不可数名词;但当表示具体的某种速度时，是可数名词。
at speed 高速地，迅速地。
at full/top speed 全速，以最快的速度。
12 ) rather
rather … than do … 是……而不是…… 相当于 more … than… or rather 更确切地说
would rather do … than do … 宁愿做……而不愿做…… would rather+ 从句(从句谓语用虚拟语气)宁愿某人…… prefer to do … rather than… 宁愿做……而不愿意做…… would tather have done …宁愿已经做了……
13 ) measure
①量尺寸，面积，与表示数量的词(短语)连用，其主语是表示物的名词。
② take sb ’ s measure 或 take the measure of sb 给某人量尺寸。
③ take measures 采取措施，这时 measure 通常用复数形式。
14 ) manage
区别 manage to do 和 try to do ：
manage to do 表示“设法成功完成(了)较困难的事情“，强调结果，相当于 be able to do sth 或 succeed in doing sth ; try to do 表示”尽力，设法去做某事“，强调目的，结果如何，不得而知。
manage 与 can 或 could 连用，表示“能办好某件难事“，口语中还可以作“吃，渡过”; manage 还可表示“经营，管理”的意思。
高中英语必修三教案 【篇4】
一、单元考点提示
1.单词
willing ,devote,cure,disadvantage,shock,institute,admire,debt,expedition,
merchant, exist,chart,botany,disaster,crew.
2.短语
devote…to 把……用在;把……献给
succeed in (干)……成功
give off 发出(光、热等)
in honour of 为了纪念……;为向……表示敬意
above all 首先;首要
set off 使爆炸;引起;出发
pay off 偿清(欠款等)
at sea 在大海上;在航海
take…by surprise 使……吃惊;出奇兵攻占
in charge of 主管;负责
set out 出发;开始
in search of 寻找
3.句型
(1)I’m (not)sure… I’m not sure whether/if…
(2)I doubt if/whether…
(3)Making a map of the east coast was an important job.
(4)The men often fall ill and suffer fever.
(5)They will provide us with eggs and meat.
4.交际英语
(1)I doubt if he’ll be asked to speak again next year.
(2)Perhaps I’ll go to that one.
(3)Maybe it was useful for some people.
(4)How did you find the talk this morning?
(5)I shall insist on leaving at 7 a.m.sharp.
(6)We’ve decided to do sth./that…
(7)Have you decided which boat to take?
(8)I suggest doing sth.
二、考点精析与拓展
1.have something(nothing,much,little)to do with与……有(没有，有很大，有一点)关系。
①I have nothing to do with that young man.
②His job has something to do with telephones.
③This has little to do with what we are talking about.
④Do you have anything to do with that club?
2.doubt v.& n.怀疑，不相信
n.
of…对……(抱)怀疑或悲观(态度)
doubt 从句在否定句及疑问句中多跟that
引起的从句，在肯定句中多跟
whether(if)引起的从句。
①I doubt the truth of this report.
②They have never doubted of success.
③I don’t doubt that you are honest.
④Can you doubt that he will win?
⑤I doubt if that was what he wanted.
该词作名词时有以下短语
beyond(all)doubt毫无疑问;in doubt怀疑，犹豫，不肯定;no doubt肯定地，想必;without doubt毫无疑问，一定地
①The truth of the story is beyond doubt.
②I was in doubt about what to do.
③No doubt I learned a lot from that lecture.
④Without doubt these theories were all wrong.
3.How do (did )you find…?(你觉得/认为……怎么样?)是征求对方对某人、某事的看法或意见的用语。回答时在find 后要跟复合宾语。
How did you find the dishes?
(I found them)Tasteless.
How do you find Peter Gray?
I found him dishonest.
4.admit vt.①接纳，许可……进入(allow sb./sth.to enter)
He was admitted to the school this year.Only two hundred boys and girls are admitted to our school every year.
②承认，后可接名词，doing、从句或复合结构。
I admit my fault.She admitted having read the letter.He admitted that his comprehension was weak.You must admit the task to be difficult.
5.be remembered as…作为……而被人们怀念
He will always be remembered as a national hero.
6. ( be)determined to do sth.下定决心做……
determine to do sth.决定(心)做……
①I was determined not to follow their advice.
②I left him,determined never to set foot in that house again.
③She determined to go that very afternoon.
7.certain某(些)，仅作形容词用法。
①He didn’t come for a certain reason.
②A certain person called on me yesterday.
③She will do it on certain conditions.
some 也可以作此意讲，但前面无冠词
①He is living at some place in East Africa.
②I’ve read that story before in some book of other.
8.succeed in sth.(doing sth.)(干……)成功，其反义词组;fail in sth.(doing sth.)或fail to do sth.;名词success;形容词successful
9.give off,放出(光、烟、气味等)、散发，
give out,放出，发出(声音，光线，气味等)，(食物、燃料、力量等)用尽、筋疲力尽。
①These red roses give off a sweet smell.
②This device gives out flashes of light in the fog.
③Both my strength and money gave out.
10.in honour of sb.(sth.) 为了纪念或表示敬意而举行某活动。
①A memorial meeting was held in his honour.
②It is only a dance in honour of my birthday.
11. devote…to…把……献给，把……用在
devote oneself to…致力于，献身于
be devoted to…专心致志于，献身于，忠于
①Mary devotes too much time to eating.
②He has devoted his whole life to benefiting mankind.
③He devoted himself entirely to music.
④He was still devoted to the study of chemistry.
⑤He is very devoted to his wife.
12.believe in 信任
①We believe in Marxism.
②You can believe in him.
③We believe in our government.
set off (for)出发，动身(去某地)
set off 引爆
13. set out to do sth.着手……
n.
set about
doing开始(着手)做……
①We’ll set off fox Xi’an at six tomorrow.
②Polonium is used to set off a nuclear bomb.
③He set out to break the record for the crosschannel swim.④I don’t know how to set about this job.
14.have effect on 对……有影响，相当于affect：
It has had such a bad effect on him.
15.above all 首先，特别是，最重要的是
after all 到底，毕竟
at all (用来加强语气)与not连用，表示“一点也不，完全不”。
in all 总共
all but 几乎，差点没(=almost,nearly)
①We have all but finished the work.
②The day turned out fine after all.
③Children need many things ,but above all they need love.
④He wasn’t at all tired.
⑤Do you feel ill at all(真的，确实)?
⑥There were twenty in all at the party.
16.order food 叫食物
order n.&vt./vi.订购……
place an order for sth.订购……
order sth.from…向……订购……
order sb.sth. order sth.for sb.为某人订购……
I have ordered you some new clothes.
17.insist on doing sth.坚持做……
suggest doing sth.建议做……
enjoy doing sth.喜欢做……
类似的admit,appreciate,avoid,consider,delay,deny,detest.dis
-like,endure,escape,excuse,face,feellike,finish,forgive,give
up,can’t help,imagine, leave off,mention,mind,miss,postp
-hone,practise,put off, resist,risk,can’t understand,und
-erstand,mean(意味着)
以上这些动词只能接动名词作宾语，不能接动词不定式作宾语。在介词之间，也只能用动名词作宾语。
Look forward to,object to ,be used to,in addition to,prefer…to,according to,stick to,etc.
18.live animals活着的动物
(动、植物等)活着的
live adj. (置于名词之前)
(广播、电视等的)实况的
作为叙述形容词则用alive,living
alive,(more alive,most alive)活着的;有活力的，活泼的;(不置于名词之前)常作表语。
a live (living) fish 一条活鱼
不能用an alive fish
a live TV broadcast实况转播的电视节目
catch a lion alive活捉狮子
①Although old,he is very much alive.
②My grandmother is more alive than a lot of young people.
③The wounded soldier is still living.
lively adj.精神的，有生气的，活泼的，生动的
a lively boy,
a lively discussion.
Her talk was lively and interesting.
19.throw away抛弃
throw in插进(话语)
throw off脱
throw out 抛出，丢弃
throw over把……抛过去(抛回)，抛弃(朋友)
20.Provide sb.with sth.供给某人……
provide it 供给……，提供……
provide:
n.eg.The hotel will provie tents.
n.+for sb. sb.+with sth.
eg.They provide food and books for the children.
They provide the children with food and books.
provide for赡养，抚养
He had to provide for a big family
supply vt.提供……供给……
n.supply
sth.to sb. sb.with sth.
They didn’t supply those children with books for studying.
They didn’t supply books to those children for studying.
21.go bad 变坏
类似的：go wrong,go mad,etc.
go 通常表示不好的变化。
Alice’s face went red with anger.
My husband’s hair is going gray.
22. at sea 在航海中，在海上
at the sea 在海边
在英语中，有许多结构用与不用定冠词在意思方面有着很大的区别。
go to sea 当水手，当海员
go to the sea 到海边去
keep house 料理家务
keep the house呆在家中不出门
in bed 睡着，躺在床上
in the bed在床上
at play在玩，正在游戏
at the play 在看戏
23.fall ill 生病，得病
①Tom is absent,for he has fallen ill.
②John was caught in the storm and he fell ill.
24.keep sb.healthy使……保持健康
keep,n.“使维持(某种状态)”后可接adj.(ving,p.p,adv.)等作宾补。
①I was so tired that I could hardly keep myself awake.
②I’m sorry to have kept you waiting so long.
③Keep your mouth shut and your eyes open.
④They kept us out.
⑤Once a cold kept him in bed for three days.
25.take an interest in 对……感兴趣
have an interest in 对……感兴趣
lose interest in 对……失去兴趣
①He has a great interest in stamp-collecting.
②I lost my interest in history.
③His father took no interest in him.
26.pay for 付……的货款，为……付代价
pay off 全部还清，偿请(借款)
①Did you pay 300 yuan to him for that bicycle?
②I have just paid off my loan from the bank.
③You’ll have to pay for your mistakes.
27.suffer v.受苦,遭受。
①She suffered greatly as a child.
②He suffered the loss of a leg during the war.
③She suffers from stomach-aches.
28.break out(战争、火灾、疾病、瘟疫等的)爆发
①The American Civil War broke out in 1861.
②Fire broke out in the neighbour last night.
break out in (into)…忽然(做出)……
break out in laughter突然放声大笑
break in (强盗等)强行闯入
break into闯入;打碎(打破)成……
break up 分开，分割
29.take…by surprise对……突然袭击，出乎……意料。
His parents took him quite by surprise when they suddenly appeared at the door.
30.in charge of prep.担任……，管理……，负责
in the charge of a personin a person’s charge由(某人)照料(管理)
take charge of 担任……，接管。
My father is in charge of this company.
31.set sail 扬帆启航
The ship set sail for Europe.
32.head south向南行
head vi.向……前进，朝某方面行进。后面接for,forward的介词短语，或表示方向的副词east,eastward等。
①Where are we heading?
②Those ships are heading for HongKong.
高中英语必修三教案
高中英语必修三教案 【篇5】
第三单元
1 ) bet
make a bet 打赌
place/put a bet on 在……下赌注
one ’ s best bet 最好的办法
作动词，表示“打赌，赌博”，后直接加宾语。
I bet ( that )表示“我敢肯定”，相当于 I am sure 。
you bet 表示“肯定，没问题”，相当于 certainly 。
2 ) scene
scene 表示“(戏剧，电影中的)一幕 / 一场，出事地点，现场，情景;风景，布景”。
behind the scenes 在幕后;秘密地。
on the scene 在现场。
set the scene ( for sth )作事前的现场描述，为……做准备。
come on the scene 到现场。
3 ) stage
表示“舞台，戏剧，阶段”，可以表示“路程，一段路，(事故发生的)现场”。
be/go on the stage 当演员，登台演出
set the stage for sth 为某事做准备。
4 ) tale
是可数名词，表示“传说，故事”。
tell its own tale 不言自喻，显而易见。
5 ) permit
作动词，后接名词或者代词，表示“允许，答应”;也可以表示“使可能”。
后接不定式的复合结构。
后接动名词，不能直接跟不定式。
分词短语作状语。
后不能跟从句。
permit of sth 认可，容忍。
作名词，表示“许可证，执照，许可”。
6 ) account
作名词，表示“叙述，报道，理由，账目，户头”。
by/from all accounts 根据大家所说的。
give an account of 叙述，报道，说明。
作名词，表示“认为”时，后接复合宾语。
account for 表示“做出解释，导致，是……的原因”，还可以表示“占，捕获”。
常见的词组：
out of account 不考虑 on all accounts/on every account 无论如何 on no account 决不
take … into account/take account of … 对……加以考虑，顾及…… turn … to good account 利用
7 ) jealous
be jealous of sb 嫉妒，唯恐某人被他人夺走。
be jealous of sth 妒忌，精心守护。
8 ) issue
作动词，表示“发行，出版，发布“。
issue sb with sth 将某物发给某人。
issue in 导致。
作名词，表示“流出，发行，(出版物的)期号，争端”。
at issue 要考虑的，意见不同的。
take issue with sb ( on/over/about )就某事论某人。
9 ) bow
bow at sb 朝某人鞠躬 bow to sb 鞠躬迎接某人
bow sb in/into 鞠躬迎入某人 bow sb out 鞠躬送走某人
bow to sth 顺从某事
take a/one ’ s bow (演员)鞠躬谢幕( bow 作名词)。
10 ) pretend
作及物动词，后接动词不定式， that 从句，名词。
pretend to sth 表示“自以为有……”，后面接名词，常指“学问，智慧，美德”。
11 )有关 trouble 的词组：
get into trouble 陷入困境，惹麻烦 ask for/look for/borrow trouble 自找麻烦，自讨苦吃
be a trouble to sb 对某人是个麻烦 be a trouble to do 干某事是件麻烦事
be in trouble 处于困境 get sb into trouble 使某人陷入困境 get out of trouble 摆脱困境
have trouble doing sth 做某事很费力 make trouble 闹事，捣乱 make trouble for sb 给某人带来麻烦 take the trouble to do sth=take the troublein doing sth 不辞劳苦地做某事 trouble sb to do sth 麻烦某人做某事 trouble sb for sth 麻烦某人某事
3. 语法
名词性从句
在句子中起名词作用的句子叫名词从句 (Noun Clauses )。 名词从句的功能相当于名词词组 , 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
一、引导名词性从句的连接词
引导名词性从句的连接词可分为三类：
连词： that (无任何词意)
whether,if (均表示“是否”表明从句内容的不确定性)
as if ,as though (均表示“好像”，“似乎”)
以上在从句中均不充当任何成分
连接代词： what, whatever, who, whoever, whom,
whose, which.whichever,whomever
连接副词： when, where, how, why
不可省略的连词：
1. 介词后的连词
2. 引导主语从句和同位语从句的连词不可省略。
That she was chosen made us very happy.
We heard the news that our team had won.
比较：
whether 与 if 均为”是否”的意思。 但在下列情况下，whether 不能被 if 取代：
1. whether 引导主语从句并在句首
2. 引导表语从句
3. whether 从句作介词宾语
4. 从句后有” or not ”
Whether he will come is not clear.
大部分连接词引导的主语从句都可以置于句末，用 it 充当形式主语。
二 . 主语从句
作句子主语的从句叫主语从句。主语从句通常由从属连词 that ， whether ，if 和连接代词 what ， who ， which ， whatever ， whoever 以及连接副词 how ， when ， where ， why 等词引导。 that 在句中无词义，只起连接作用;连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。
有时为避免句子头重脚轻，常用形式主语 it 代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：
( 1 ) It + be + 名词 + that 从句
( 2 ) It + be + 形容词 + that 从句
( 3 ) It + be + 动词的过去分词 + that 从句
( 4 ) It + 不及物动词 + that 从句
另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“ (should) +do ”，常用的句型有：
It is necessary (important, natural, strange, etc.) that …
It is a pity (a shame, no wonder, etc.) that …
It is suggested (requested, proposed, desired, etc.) that …
三、宾语从句
名词句用作宾语的从句叫宾语从句。引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作谓语动词或介词及非谓语动词的宾语。
1. 由连接词 that 引导的宾语从句
由连接词 that 引导宾语从句时， that 在句中不担任任何成分，在口语或非正式的文体中常被省去，但如从句是并列句时 , 第二个分句前的 that 不可省
注意：在 demand 、order 、suggest 、decide 、insist, desire, request, command 等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“( should ) + 动词原形”。
2. 用 who ， whom, which, whose, what, when, where, why, how, whoever, whatever,whichever 等关联词引导的宾语从句相当于特殊疑问句，应注意句子语序要用陈述语序。
3. 用 whether 或 if 引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述句语序。此外， whether 与 if 在作“是否”的意思讲时在下列情况下一般只能用 whether ，不用 if ：
a. 引导主语从句并在句首时;b. 引导表语从句时; c. 引导从句作介词宾语时;d. 从句后有“ or not ”时; e. 后接动词不定式时。
4. 注意宾语从句中的时态呼应，当主句动词是现在时，从句根据自身的句子情况，而使用不同时态。
当主句动词是过去时态( could, would 除外)，从句则要用相应的过去时态，如一般过去时，过去进行时，过去将来时等;当从句表示的是客观真理，科学原理，自然现象，则从句仍用现在时态。
5. think, believe, imagine, suppose 等等动词引起的否定性宾语从句中，要把上述主句中的动词变为否定式。即将从句中的否定形式移到主句中。
四、表语从句
在句中作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，有时用 as if 引导。其基本结构为：主语 + 系动词 + that 从句。
需要注意的，当主语是 reason 时，表语从句要用 that 引导而不是 because 。
【注意】 whether 可引导表语从句，但与之同义的 if 却通常不用于引导表语从句。
五、同位语从句
同位语从句说明其前面的名词的具体内容。同位语从句通常由 that 引导，可用于同位语从句的名词有 advice 、demand 、doubt 、fact 、hope 、idea 、information 、message 、news 、order 、problem 、promise 、question 、request 、suggestion 、truth 、wish 、word 等。
同位语从句和定语从句的区别：
that 作为关系代词，可以引导定语从句，充当句子成分，在从句中作宾语时可以省略; that 引导同位语从句时，起连词的作用，没有实际意义，不充当句子成分，一般不能省略。
试比较下面两个例句 :
I had no idea that you were here .( that 引导同位语从句，不能省略)
Have you got the idea ( that ) this book gives you of life in ancient Greece ?( that 引导定语从句，作宾语，可以省略)
六、名词性 that- 从句
1 )由从属连词 that 引导的从句叫做名词性 that- 从句。 That 只起连接主句和从句的作用，在从句中不担任任何成分，本身也没有词义。名词性 that- 从句在句中能充当主 语、宾语、表语、同位语和形容词宾语，例如：
主语： That he is still alive is sheer luck. 他还活着全靠运气。
宾语： John said that he was leaving for London on Wednesday. 约翰说他星期三要到伦敦去。
表语： The fact is that he has not been seen recently. 事实是近来谁也没有见过他。
同位语：The fact that he has not been seen recentlydisturbs everyone in his office.
近来谁也没有见过他，这一事实令办公室所有的人不安。
形容词宾语： I am glad that you are satisfied with your job.
你对工作满意我感到很高兴。
2 ) That- 从句作主语通常用 it 作先行词，而将 that- 从句置于句末，例如：
It is quite clear that the whole project is doomed to failure. 很清楚，整个计划注定要失败。
It ’ s a pity that you should have to leave. 你非走不可真是件憾事。
用 it 作形式主语的 that- 从句有以下四种不同的搭配关系：
a. It + be + 形容词 + that- 从句
It is necessary that … 有必要……
It is important that … 重要的是……
It is obvious that … 很明显……
b. It + be + -ed 分词 + that- 从句
It is believed that … 人们相信……
It is known to all that … 从所周知……
It has been decided that … 已决定……
c. It + be + 名词 + that- 从句
It is common knowledge that ………是常识
It is a surprise that … 令人惊奇的是……
It is a fact that … 事实是……
d. It + 不及物动词 + that- 分句
It appears that … 似乎……
It happens that … 碰巧……
It occurred to me that … 我突然想起……
七、名词性 wh- 从句
1 )由 wh- 词引导的名词从句叫做名词性 wh- 从句。 Wh- 词包括who, whom,. whose, whoever, what, whatever,which, whichever 等连接代词和 where, when, how, why 等连接副词。 Wh- 从句的语法功能除了和 that- 从句一样外，还可充当介词宾语、宾语补语和间接宾语等，例如：
主语： How the book will sell dependson its author. 书销售如何取决于作者本人。
直接宾语： In one ’ s own home one can do what one likes. 在自己家里可以随心所欲。
间接宾语： The club will give whoever wins a prize.
俱乐部将给得胜者设奖。
表语： My question is who will takeover president of the Foundation. 我的问题是谁将接任该基金会主席职位。
宾语补足语： She will name him whatever she wants to. 她高兴给他起什么名字就取什么名字。
同位语： I have no idea when he will return.
我不知道他什么时候回来。
形容词宾语： I ’ m not sure why she refused their invitation. 我尚不能肯定她为什么拒绝他们的邀请。
介词宾语： That depends on where we shall go.
那取决于我们去哪儿。
2 ) Wh- 从句作主语也常用先行词 it 做形式主语，而将 wh- 从句置于句末，例如：
It is not yet decided who will do that job.
还没决定谁做这项工作。
It remains unknown when they are going to get married. 他们何时结婚依然不明。
八、if, whether 引导的名词从句
1 ) yes-no 型疑问从句
从属连词 if, whether 引导的名词从句是由一般疑问句或选择疑问转化而来的，因此也分别被称为 yes-no 型疑问句从句和选择型疑问从句，其功能和 wh- 从句的功能相同， 例如：
主语： Whether the plan is feasible remains to be proved. 这一计划是否可行还有等证实。
宾语： Let us know whether / if you can finish the article before Friday. 请让我们知道你是否能在星期五以前把文章写完。
表语： The point is whether we should lend him the money. 问题在于我们是否应该借钱给他。
同位语： They are investigating the question whether the man is trustworthy. 他们调查他是否值得信赖。
形容词宾语： She ’ s doubtful whether weshall be able to come. 她怀疑我们是否能够前来。
介词宾语： I worry about whether he canpass through the crisis of his illness. 我担心他是否能度过疾病的危险期。
2 )选择性疑问从句
选择性疑问从句由关联词 if/whether … or 或 whether … or not 构成，例如：
Please tell me whether / if they are Swedish or Danish. 请告诉我他们是瑞典人还是丹麦人。
I don ’ t care whether you like the plan or not. 我不在乎你是否喜欢该计划。
if 和 whether 的区别：
1 、在动词不定式之前只能用whether 。
2 、在 whether …… ornot 的固定搭配中。
3 、在介词后，只能用whether 。
4 、宾语从句放在句首表示强调时，只能用 whether 。
5 、用 if 会引起歧义时，只用 whether 。
九、否定转移
1) 将 think,believe, suppose, expect, fancy, imagine 等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式。注意：若谓语动词为 hope, 宾语从句中的否定词不能转移。
2) 将 seem,appear 等后的从句的否定转移到前面。
3) 有时将动名词，介词短语或整个从句的否定转变为对谓语动词的否定。
4) 有时状语或状语从句中否定可以转移到谓语动词前。
