She may have missed the train, in which case she won’t arrive for another hour.
THAT 多用于同位语从句和－thing的定语从句中。
WHAT
(有实际意义，可用于宾语从句和主语从句)
1. No one knows exactly what happened.
2.It is not clear to what extent these views were shared.
3.I could get you a job here if that’s what you want.
4. What that kid needs is some love and affection.
5. What matters is the British people and British jobs.
AS
1.比较
His last album sold half a million copies and we hope this one will be just as popular./ They want peace as much as we do.
2.作为，正如… We’d better leave things as they are until the police arrive.
David, as you know, has not been well lately.
3.看作，看待
The result of last week’s election will be seen as a victory.
4.当…时候= while or when
I saw Peter as I was getting off the bus.
5.原因 As it was getting late, I turned around to start for home.
6.让步= though Try as she might, Sue couldn’t get the door open.
The bag has narrow straps, so it may be worn over the shoulder or carried in the hand.
I’d be in trouble if I let on. So I kept mum.
When the meal was finished, Rachel washed up and made coffee.
I would have liked to have learnt French, but I was denied (=not given) the opportunity.
The opportunity was denied (to) me at school.
The prestige is denied (to) the classroom teacher.
The classroom teacher is denied the prestige.
过去分词与形容词的语义差：
1.Destructive:causing damage to people or things
the destructive power of modern weapons
Damaged: being in a bad state
emotionally damaged children
2.Respected:admired by many because of achievements
He’s one of the most respected managers in the game.
Respectful: feeling or showing respect
They listened in respectful silence.
3. Preferred : Her own preferred methods of exercise are hiking and long cycle rides.
Preferable: A big earthquake a long way off is preferable to a smaller one nearby.
Preferential: Bank officials denied giving the senator any preferential treatment.
4. Unimagined:Others see a new golden age of business and technology that will lift the market to unimagined heights.
Unimaginative:That means the traditional office layout of lined-up cubicles and work stations is seen as rigid and unimaginative.
5.Loving: She was a devoted wife and a very loving mother.
Lovable: a sweet lovable child
Lovely: We had a lovely holiday.
6. Tolerated: While Patches are generally well tolerated they are not always suitable for everyone.
Tolerant: trees that are tolerant of salt sea winds
Tolerable: All in all, it was better to have a tolerable tenement than the ideal which no one could afford.
虚拟语气
非谓语动词主要包括不定式、动名词和现在分词。为了区分这三种不同的非谓语动词的用法和含义，我们将分别从三种非谓语动词在句子中做主语、宾语、宾语补足语、定语、状语、表语以及一些特殊结构句型等角度来区分其用法和细微含义。
1．不定式和动名词作主语的区别
(1)动名词作主语通常表示抽象动作；而不定式作主语表示具体动作。
Smoking is prohibited(禁止)here．这里禁止抽烟。(抽象)
It is not very good for you to smoke so much．你抽这么多烟对你身体很不好。(具体)
(2)动名词作主语时，通常用以表示一件已知的事或经验。
不定式短语通常用来表示一件未完成的事或目的。
Climbing mountains is interesting．爬山很有趣。(经验)
Driving a car during the rush hour is tiring．在高峰时刻开车令人厌烦。(经验)
（3）不定式做主语，一般用it当形式主语，把作主语的不定式短语后置。
It took me only five minutes to finish the job.
2．不定式、动名词和分词作表语的区别
(1)不定式作表语
1)不定式作表语一般表示具体动作，特别是表示将来的动作。
To do two things at a time is to do neither．--次做两件事等于未做。
What I would suggest is to start work at once.我的建议是立刻开始干。
2）如果主语是不定式（表示条件），表语也是不定式（表示结果）。
To see is to believe.百闻不如一见。
To work means to earn a living．工作就是为了生活。
3)如果主语是以aim，duty，hope，idea，happiness，job，plan，problem，purpose，thing，wish等为中心的名词，或以what引导的名词性从句，不定式作表语是对主语起补充说明作用。
His wish is to buy a luxurious car in the near future．他的希望是在不远的将来买一辆豪华轿车。
The function of Louis Sullivan’s architecture was to provide large uninterrupted floor areas and to allow ample light into the interior.
The most important thing is to negotiate with them about the future of the plant．
(2)动名词作表语：动名词作表语，表示抽象的一般性的行为。
Our work is serving the people．我们的工作是为人民服务。
His hobby is collecting stamps．他的爱好是集邮。
