Working 12 hours a day exhausts me completely. 每天工作12小时让我筋疲力尽。(动名词具有名词的特征，在没有特指是谁发出这个动作的情况下，可以不考虑其逻辑主语，因为在语境中一眼就能看出是谁发出的动作，比如本句话，主语working 12 hours a day当然是句中的“我"发出的动作)。本句如果改成主语从句，那就是: That I work 12 hours a day exhausts me completely. 但是这里用主语从句，远远不如用动名词短语作主语简洁明了。
Playing football is my favorite sport.踢足球是我最喜欢的运动。
No good thing can be enjoyed by us, without having cost labor. 不付出辛劳，我们就不能享受任何美好的事物。(完成态，主动语态)。本句如果用No good thing can be enjoyed by us, without costing labor.也不算错误，但是用完成态更好，因为是先劳动，再享受。
I appreciate having been given the opportunity to study abroad two years ago.我很感激两年前得到一次出国留学的机会。(完成态，被动语态)
两个短语为固定搭配，虽说是主动的形式，但表达被动的含义
sth. need doing: 某事需要被做
The classroom is so dirty that it needs cleaning thoroughly. 教室很脏，需要彻底清洁。
sth. be worth doing: 某事值得被做
By this time, a Lancaster bomber in reasonable condition was worth rescuing. 这个时候，一架状态良好的lancaster轰炸机是值得拯救的。
造句练习
1.这台电视机开关的声音在大街上都能被听到。
1.The noise of the television being opened and closed can be heard in the street.
2.我一直后悔上学时没有更加努力的学习。
2.I have always regretted not having studied harder at school.
3.墙角处的那个人承认对这家公司的经理撒了谎(tell a lie)。
3.The man in the corner confessed to having told a lie to the manager of company.
To make large sums of money is my dream. 挣大钱是我的梦想。(相当于That I wilI make large sums of money is my dream)
注意:如果本句用Making large sums of money is my dream. 也对，但是用不定式暗示“我要去挣钱”，但目前还没有挣到钱。现代英语中，不定式和动名词作主语一般可通用。
不定式作主语时，可用形式主语It取代，然后将不定式放在句子主干之后
It was his job to repair bicycles and at that time he used to work fourteen hours a day.他那时的工作是修理自行车，并且通常是一天工作14个小时。(相当于It was his job that he repaired bicycles...)
So, it comes as a surprise to learn that giant fish are terrifying the divers on North Sea oil rigs. 因此，听说北海石油钻井平台上的潜水员受到巨型鱼类的恐吓，确实很让人吃惊。(相当于it comes as a surprise that we learn giant fish ....)
大部分及物动词，其后即可用不定式，也可用动名词，比如begin doing = begin to do
但是表示“企图”或者“意愿”的及物动词，其宾语是“将要发生的事情”，所以通常只能用不定式作宾语
Debbie is only eleven years old and she hopes to set up a new world record. 黛比只有11岁，她希望创一项新的世界纪录。(相当于...that she can set up a new world record. )
Last Christmas, the circus owner, Jimmy Gates, decided to take some presents to a children's hospital. 去年圣诞节，马戏团老板吉米.盖茨决定送些礼物给儿童医院。
It has four Rolls-Royce Merlin engines, but the group will need to have only three of them rebuilt. 该飞机装装配有4台罗尔斯-罗伊斯的默林发动机，但是他们只需要修复其中的3台。(相当于...that they will have only three of them rebuilt. )
The pilot managed to circle the balloon for some time. 飞行员设法绕着气球飞了一阵。
The majority of people seemto prefer TV to radio. 多数人喜欢电视胜过广播。
These birds seemunaffected by climate.这些鸟似乎不受气候的影响。
He appearsa perfectly normaI person. 他看上去是一个完全正常的人。
The search proveddifficult. 这次搜索被证明是很困难的。
He turned outto be right. 结果他是对的。
Babies of two months old do not appearto be reluctant to enter the water. 两个月的婴儿并未显得不愿意入水。
By this time, a Lancaster bomber in reasonable condition was worth rescuing. 这个时候，一架状态良好的lancaster轰炸机是值得拯救的。
The operation, which lasted for over four hours, provedto be very difficult because of the hard resin which covered the skin. 手术持续了4个多小时，非常难做，因为皮肤上覆盖着一层硬硬的树脂。
作宾语补语 或 被动语态的主语补语：此时不定式如果是to be，可以省略
She wanted him to repair their son's bicycle! 她叫他去修理孙子的自行车。
When it was eventually brought to shore, it was found to be over thirteen feet long. 当终于把它弄上岸后，人们发现它身长超过了13英尺。(本句中to be可省略)
作同位语
My plan to visit the town was refused. 我的参观小镇这个计划被拒绝了。
(相当于同位语从句My plan that I will visit the town was refused. )
疑问词+不定式：构成名词短语，用法和名词相同
I was just wondering how to spend the morning. 我正不知道怎么消磨这一上午呢。
(相当于宾语从句I was just wondering ^how I would spend the morning.` )
Fifteen policemen had to push very hard to get him off the main street. 15个警察不得不用很大的力气把它推离主要街道。(相当于目的状语从句... that they could get him off...)
When the bull got close to him, he clumsily stepped aside to let it pass. 当公牛逼近他时，他踉跄地住旁边一闪，牛扑空了。(相当于目的状语从句....so that he could let it pass. 由于let是不完全及物动词，故此不定式短语类似第四大句型，it是不定式to let的宾语，pass是宾语补语. )
It was not long before a helicopter arrived on the scene to rescue the survivors of the plane crash. 不久，一架直升飞机飞抵飞机失事现场，来搭救这几个幸存者。(相当于目的状语从句...so that it could rescue...)
Specially-made lanterns are hung outside each house to help the dead to find their way. 特制的灯笼挂在各家的门外，为的是帮助亡灵看清道路。(相当于 目的状语从句.... that they could help the dead..由于heIp是不完全及物动词，故此不定式短语类似第四大句型)
有时候为了强调目的状语，可以将不定式放在句首
To acquire knowledge, one must study; but to acquire wisdom, one must observe. 要想获得知识，就必须学习，但是要想获得智慧，就必须学会观察。
To be really happy and really safe, one ought to have at least two or three hobbies, and they must alI be real. 要想真正幸福和平安，一个人至少应该有两三种业余爱好，而且必须是真正的爱好。
作结果状语（不定式表示意料之外的结果，而分词短语表示意料之中的结果）
Farm laborers said that they always woke up to find the work had been done overnight. 农场工们说，常常一早起来却发现有人在夜里把活干了。(意料之外)
The small company has beaten other big companies, to win the title of best business-class service. 这个小航空公司击败了其他大公司从而赢得了最佳商务舱服务奖。(意料之外)
造句练习
1.憎恨别人，犹如为了除掉一只老鼠而烧掉自己的房子。
Hating people is like burning down your own house to get rid of a rat.
He expects for his sister to meet you. 他期望他妹妹认识你。(相当于He expects that his sister can meet you. )
There is no need for you to go. 你没有必要去。
Dentists always ask questions when it is impossible for you to answer. 牙科医生们总是在你无法作出回答的时候向你提出问题。
Chinese parents wanted their children to be successful, while American parents expressed a desire for their children to be happy. 中国的父母希望孩子成功，而美国的父母表达了他们的愿望，那就是希望他们孩子幸福。
表达“对于...来说做某事是怎样的”，通常都可以采用这种不定式带上逻辑主语的结构：It is + 形容词 + for sb. to do sth.
It is necessary for him to study English every day. 对于他来说，每天学习英语是很有必要的。
代词作不定式的逻辑主语时，用宾格。
My sister told me that she would love for me to babysit for her. 姐姐告诉我她很想要我帮她照顾小孩
在It is + 形容词 + for sb. to do sth.句型中，表示人物性格的形容词（聪明，善良，粗心，愚蠢。。等）和不定式连用时，要用of代替for
It's wise of you not to argue with your boss. 明智的做法是不和你的老板争吵。
It was very careless of him to make such silly mistakes. 他太粗心了，居然犯了如此愚蠢的错误。
造句练习
1.此刻，我很难表达我的心情。
It’s very difficult for me to express my feelings at this moment.
He wanted some photographs to be taken when he visited Taiwan. 他在台湾参观的时候想找人拍几张照片。(一般态，被动语态)
不定式的完成态，表示不定式的动作发生在谓语动作之前
Fisherman and sailors sometimes claim to have seen monsters in the sea. 渔夫和水手们有时声称自己看到过海里的妖怪。(完成态，主动语态)
This building was said to have been built from their own designs.这据说是他们自行设计建造的。(完成态， 被动语态)
常见固定搭配
claim to do: 宣称
be said to do: 据说
be supposed/thought/expected to do: 应该
Everyone went to the funeral, for the 'ghost' was none other than Eric Cox, a third brother who was supposed to have died as a young man. 大家都去参加了葬礼，因为那“鬼”不是别人，正是农场主的兄弟埃里克.考科斯。人们以为埃里克年轻时就死了。
When I was a boy, my grandfather told me how a German taxi driver, Franz Bussman, found a brother who was thought to have been killed twenty years before. 当我是个孩子的时候，我祖父给我讲了一位德国出租汽车司机弗朗兹.巴斯曼如何找到了据信已在20年前死去的兄弟的事。
If Peter should come again, I would throw him out. 如果彼得再来的话，我会把他轰出去。
过去虚拟
If, at the time, the British had not feared invasion, the tunnel would have been completed. 如果不是因为那时英国人害怕入侵，隧道早已建成了。
If the Houses of Parliament had not been burned down in 1834, the great clock would never have been erected. 如果不是国会大厦在1834年被焚毁的话，这座大钟永远也不会建造。
If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours. 如果不是因为土壤下面有一层坚硬的岩石，他们的营救工作仅用几个小时就可以完成了。
补充：if从句中的were, should, had可以放在主语前，同时省略if
If he were here, I would tell him the truth. = Were he here, I would tell him the truth.
If it should rain, our plan would be spoiled. = Should it rain, our plan would be spoiled.
If you had helped me, I could have finished the work on time. = Had you helped me, I could have finished the work on time.
“Should humanity leave Earth to travel across the universe," she said, concluding her impassioned explanation, “it would be no different from an infant leaving its mother in the middle of a desert!" “人类在宇宙间离开了地球，”她充满激情地说，“就像婴儿在沙漠中离开了母亲!” ——《The wandering earth》Liu Cixin (刘慈欣《流浪地球》)
造句练习
1.如果当时你帮助我的话，我就可以完成任务了。(当时你没有帮助我)
1.If you had helped me then, I would have accomplished the mission.
2.要是我是你，我会坐地铁去那儿。(可惜我不是你)
2.If I were you, I would go there by subway.
3.如果我有100万美元，我就会买一套豪华别墅。(可惜我是穷光蛋)
3.IfI had a million dollars, I would buy a luxury villa.
4.万一火山爆发了，有可能造成一场可怕的灾难。
4.If the volcano should erupt, it would cause a terrible disaster.
Cooked in wine, snails are a great luxury in various parts of the world. 蜗牛加酒烧煮后，便成了世界上许多地方的一道珍奇的名菜。 (因为主句是一般现在时，所以本句的分词短语是真实条件，相当于真实条件状语从句If snails cooked in wine, ...)
Weather permitting, we'll go fishing. 如果天气允许，我们就去钓鱼。(因为主句是一般将来时，所以本句的分词独立主格结构是真实条件，相当于真实条件状语从句If weather permits, we'll go fishing. )
Added to steel, chromium increases the metal's hardness. 把铬加进钢里，能增加钢的硬度。(相当于真实条件状语从句If chromium is added to steel, it increases the metal's hardness.)
Given more time, I would be able to complete it. 如果多给我一些时间，我就能把它做完。(相当于虚拟条件状语从句If I were given more time, I would be able to complete it.)
Given the right kind of training, these teenage soccer players may one day grew the international stars. 如果给予适当形式的训练，这些十几岁的足球运动员有一天会成为国际明星。
与客观真理相反的强烈虚拟语气，从句用were to + 动词原形，主句用过去将来时(would可改为should, might, could)
If I were to live my life over again, I would have you as my wife. 如果有来生，我一定娶你为妻。
If the sun were to rise in the west, I would marry you. 要想我嫁给你?除非太阳从西边出来。
主观意志动词“建议”，“要求”，“命令”3大类之后的宾语从句，要使用助动词should(可省略)
建议：suggest, advise, propose
He suggested that a double railway tunnel (should) be built. 他提议建一条双轨隧道， 这样就解决了通风问题。
要求：demand, require, request, insist
In life, your goals may require that you (should) try different approaches and persevere. 生活中，你的目标或许要求你尝试不同的方法，然后持之以恒。
命令：order, command
should (ought to) have + 过去分词，表示与过去事实相反的推测，译为“早应，本应该...”
He should have known that the police would never allow this sort of thing. 他本该知道警察绝不会允许这类事情发生。
Those who failed to get in need not have felt disappointed as many of the artistes who should have appeared did not come. 那些没能进到场内的人没有必要感到失望，因为很多应该出场的专业演员都没有来。
A policeman approached Jimmy and told him he ought to have gone along a side-street as Jumbo was holding up the traffic. 一个警察走过来告诉吉米，他应该走一条小路，因为江波阻碍了交通。
Whether it be bird, fish or beast, the porpoise is intrigued with anything that is alive. 海豚对凡是活的东西都感兴趣，不管是鸟、是鱼，还是野兽。也可变成Be bird, fish or beast, the porpoise is intrigued with anything that is alive.
After all, all living creatures live by feeding on something else, whether it be plant or animal, dead or alive. 因为一切生物都靠吃别的东西来活命，不管这种东西是植物还是动物，死的还是活的。
Be it a rock or a grain of sand, they sink as the same in water. 无论是岩石还是沙粒，在水中都会沉没。
All students of English, be they native speakers or those who are studying English as a second language, will profit from this book. 所有学习英语的学生都将从本书中受益，不管是把英语作为母语还是第二语言的学生。
wish后面的宾语从句，必须使用虚拟语气
现在虚拟，用一般过去时。
I wish he were here. 我真希望他在这儿。
过去虚拟，用过去完成时。
I wish I had kept faithful to my childhood dreams. 我希望当初信守儿时的梦想。
将来虚拟，用过去将来时。(would 可改为should, might, could)
I wish you would keep on trying to improve your English. 我希望你继续坚持提高英语水平。
if only用于虚拟，表示“要是...该多好啊”（时态变化同wish）
If only he were here. 要是他在这儿该多好啊!
If only I had known it earlier. 要是我早点知道这件事该多好啊。
If only I would make a lot of money. 要是我发财该多好啊。
as if/ as though用于虚拟，表示“就像...一样”（时态变化同wish）
He acted as if he had never lived in England before. 他的举动就好像他从未在英国生活过一样。
I do not turn for protection to dreary cliches about respect of elders -- as if mere age were a reason for respect. 我不会用应当尊重长者这一套陈词滥调来为我自己辨护，似乎年长就是受人尊敬的理由。
I felt as if I had stumbled into a nightmare country, as you sometimes do in dreams. 我感到自己就像平时作梦那样迷迷糊糊地闯进了恶梦境地。就像在恶梦里一样。
It looks as if there would be an exciting race across the Channel. 看来会有一场激烈的飞越英吉利海峡的竞争。
would rather / would sooner用于虚拟，表示“宁可....”
现在和将来虚拟，均用一般过去时
I would rather you had more health than wealth. 我宁愿你有更多的健康而不是财富。(现在虚拟)
I would rather my father kept his mind and body active after he retires in three years. 我宁愿三年后父亲退休以后能保持身心活跃。(将来虚拟)
过去虚拟，用过去完成时
I would rather my son had become a doctor, but he became a teacher after graduating. 我宁愿我儿子做一名医生，但是他毕业后当了教师。
