不可小觑的That
深圳市宝安高级中学 顾永
That是一个十分活跃的常用词，在中学英语中出现的频率很高，其用法也较为复杂，千万不可轻视。下面拟就其用法作一简单的归纳，便于同学们复习掌握。
一、作形容词，在句中充当定语，意为“那”、“那个”（其复数形式为those），例如：
This radio is more expensive than that one.
I didn’t feel very well that morning.
That可用于“that (或this/those/these) + 名词 + of + 名词性物主代词或名词所有格”结构中，表示赞赏、不满、厌恶等感情色彩，例如：
That remark of yours is quite correct.
That son of Peter’s is always asking some silly questions.
二、作指示代词，在句中充当主语、宾语等（其复数形式为those）。
1、代指（距离较远的）那个人或物，例如：
That is his sister Mary.
This is a car; that is a jeep.
2、代指前面提到的某事或所说的情况，例如：
That happened twenty years ago.
How to do it better and faster, that is the question.
3、代替前面出现的名词，以避免重复，例如：
The volume of the sun is much larger than that of the earth.
The cost of oil is less than that of gas.
这时应注意that与one和it的区别：
That用于特指；它既可以代替可数名词，也可以代替不可数名词，但它只能代替物，不可代替人，且其后多有后置定语。
One用于泛指；它可以代替物，也可以代替人，但它只能代替单数可数名词（复数则用those），不能代替物质名词和抽象名词；表示特指可用the one，等于that；例如：
I haven’t got an umbrella, and I am going to buy one.
He is not one to bow before difficulties.
It用于指代前面所提到的同一事物，例如：
I bought a watch last week but I lost it this morning.
三、作副词，在句中充当状语，修饰形容词和副词，意为“那么，那样，这么”，例如：
The old man is too old to walk that far.
How could she sing that well after only one lesson?
That的这种用法相当于so，但是不能与从句连用。
四、作关系词，有下列几种用法：
1、作关系代词，引导定语从句，在从句中充当主语和宾语，可以指人，也可以指物，例如：
He is the engineer that designed the new machine.
They live in a house that was built thirty years ago.
She is the girl that I saw in the park.
Is there anything (that) I can do for you?
这里需要注意的是：
① that 引导定语从句时，它本身在从句中充当一个成分，这是区别that引导定语从句与其它从句的一个重要的标志；
② that 不可以用来引导非限制性定语从句；
③ that 在从句中充当宾语时，在非正式文体或口语中常常可以省略；
④ that 在从句中充当介词宾语时，不可紧跟在介词之后（这时指人需用whom，指物需用which）；
⑤ 在一般情况下，that指人时，可以和whom互换，指物时，可以和which互换，但是在下列情况中，宜用that：
a、当先行词是all、a lot、a little、few、much、none、anything、everything、something、nothing等词时，例如：
All that can be done has been done.
b、当先行词被all、any、no、much、little、few、every等限定词所修饰时，例如：
There’s no / little time that we can spare.
c、当先行词是形容词最高级或序数词、以及先行词被形容词最高级或序数词所修饰时，例如：
He is one of the best players that our team has ever had.
This is the first time that I have heard of him.
d、当先行词被the very、the only、the next、the last等所修饰时，例如：
He is the only person that we can rely on.
e、当主句是以who、which开头的特殊疑问句时，例如：
Which is the book that belongs to me?
f、当先行词同时包括人和物时，例如：
He talked about the teachers and schools that he had visited.
2、作关系代词，引导定语从句，在从句中充当表语，可以指人，也可以指物，但往往可以省略，例如：
She is not the young and lovely nurse that she was ten years ago.
This is no longer the dirty place (that) it used to be.
注意：能在定语从句中作表语的关系代词只有that一词。
3、作关系副词，引导定语从句，配合上下文代替关系副词why、when、where或代替at which、by which、in which、with which等，例如：
This is the reason that (=why) the question should not be considered in isolation.
The Chinese delegation sat in the same row that (=where) the Canadian delegation did.
Each time that (=when) he came, he did his best to help us.
This is not the way that (=by which) we came last time.
They shouted with the loudest voice that (=with which) they could.
4、用在“It is / was …that …”结构中，对某一成分加以强调；被强调的部分可以是主语、宾语、宾语补足语或状语，例如：
It is the young man over there that teaches us English.
It was your brother that I met in the park this morning.
It was in 1985 that he was set free.
It was chairman of the committee that they elected him.
这里需要注意的是：
① 被强调的成分是人时，可以使用who,较为正式；
② 强调时间状语、地点状语不用when，where；
③ 被强调的部分不可以是表语、谓语动词、让步状语从句、比较状语从句或以as、since引导的原因状语从句。
五、作从属连词，引导名词性从句；that在句中没有词汇意义，只起连接作用。
1、引导主语从句，例如：
⑴ That Peter should have won the first place is surprising.
That引导的从句作主语时，通常使用先行it代之，而将that从句置于句子末尾，这时that可以省略，例如：
⑵ It is surprising (that) Peter should have won the first place.
在正式文体中，为了强调that从句的内容而将其置于句首时，that不可以省略（如上述⑴）；如果整个句子为疑问句，则只能使用先行it结构，例如：
Is it true that he will come here next week?
这里需要注意的是：
① 在使用it为先行主语的结构中，当表语是表明说话人态度或愿望的形容词（即句子含有建议、命令、要求等主观意向时）；或者表语是表示惊讶、喜悦、遗憾等感情色彩的形容词时，that从句中的谓语要用虚拟语气，即用“动词原形”或者“should + 动词原形”，以及“should + have+过去分词”，例如：
It is necessary that he (should) be sent there at once.
It’s important that everybody (should) be told all the facts.
It is strange that she should have left with the lights still on.
常用于这种结构的形容词有：necessary、important、best、essential、surprising、strange、impossible、natural、right、unfortunate等。
②在it is a pity / a shame / no wonder / no surprise这类结构中，并且表示惊奇、惋惜等感情色彩时，其后的that从句也应使用上述虚拟语气，例如：
It is a pity that he should refuse to go with us.
③在it is suggested / hoped / ordered / demanded / requested这类结构中，如果表示命令、建议、要求等意义，其后面的that从句也应使用上述虚拟语气，例如：
It is demanded that he (should) leave at once
④that从句作主语时，还常用于“It + appear / seem / happen + that从句”这种结构，这时它可以转换成带有不定式的简单句，例如：
It appeared that he was talking to himself.
= He appeared to be talking to himself.
It seemed that she had lost something.
= She seemed to have lost something.
It happened that he had heard of the place.
= He happened to have heard of the place.
2、引导宾语从句，例如：
He told me that he had been there many times.
这里需要注意以下问题：
① 在表示命令、建议、要求、决心、愿望等动词后的宾语从句中，谓语常用虚拟语气，即使用“动词原形”或“should + 动词原形”，例如：
We suggested that he (should) come another day.
这类动词有：advise、ask、beg、decide、desire、demand、insist、determine、order、plan、request、require、suggest等。
② 当主句的谓语动词为thank、believe、suppose、guess、expect、imagine等，表示“认为、猜想”时，其后的that从句如果带有否定意义，应注意将否定词转移到主句，例如：
I don’t suppose that you need to worry.
③ 当that引导的宾语从句后跟补足语时，应采用先行it作宾语，而将that从句置于句子的后部，例如：
We think it necessary that you should attend the meeting.
3、引导表语从句，例如：
The fact is that all bodies possess weight.
当表示建议、命令、要求、决心等动词的同源名词以及motion、opinion、idea等名词作主语，以that引导的从句作表语时，也应使用上述虚拟语气，例如：
My suggestion is that we (should) visit the Great Wall first.
Our plan is that we (should) have a sports meet next week.
4、引导同位语从句，例如：
There can be no doubt that we shall succeed.
表示命令、建议、要求、决心等动词的同源名词，以及motion、opinion、idea等名词后面的同位语从句，也应使用上述虚拟语气，例如：
What do you think of our plan / suggestion that we (should) put off the meeting till next Monday?
5、引导从句与某些充当表语、表示思想状态或感情色彩的形容词连用。这种句型中的主语一般都是人称代词，在非正式文体中that可以省略，例如：
We are sure that our team will win.
I’m glad (that) you are all right.
这类形容词有：certain、sure、glad、happy、delighted、afraid、surprised、sorry、confident、anxious等。
六、作从属连词，引导某些状语从句：
1、引导目的状语从句，用that、so that、in order that或for fear that，从句中一般有can、may、could、might、will、would、should等情态动词，例如：
Bring it closer (so) that I may see it better.
I hid the book in order that he should not see it.
I put down his address for fear that I should forget it.
2、引导结果状语从句和程度状语从句，用that、so that、so…that、such…that、such that，例如：
The sound is so weak that you can’t hear it.
Something may be wrong (so) that the machine has stopped running.
这里需要注意的是：
① 当so修饰动词时，朗读时后面应稍加停顿，例如：
His heart beat so … that he could hardly breathe.
②当so位于句首时，主句的语序须倒装，例如：
So badly was he injured that he had to go to the hospital.
③ 在so和such结构中，that有时可以省略，特别是在非正式文体和口语中，例如：
I was having such a nice time (that) I didn’t want to leave.
3、引导原因状语从句，用now that（既然）in that（因为）not that… but that（不是由于……而是因为……），例如：
Now that you mention it, I do remember.
In that he is the monitor, he should preside at the meeting.
Not that the book is difficult to read, but that he has no time.
七、作从属连词，引导表示愿望、惊奇、感叹、沮丧等情绪的从句，主句常常省略，例如：
Oh, that I were with her now!
Oh that the rain would stop.
八、介词不能和连词that一起使用，在“不及物动词+介词（相当于一个及物动词）”的结构中，在介词后应先用先行词it，然后再接that从句，例如：
You may depend upon it that all the goods will be delivered in time.
We will answer for it that this answer is right.
或者采取下列方式：
The judge held the parents responsible for the fact that the child had run away.
以上只是对that的一些常见的用法作一简单的介绍，在复习中还应注意它与其他词的区别、联系及转换关系等，并通过广泛的阅读和适量专项训练牢固地掌握其用法。
（2017-12-06）
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