课本中不会教你的[I]403 it用于强调结构
403 it用于强调结构
① 无人称代词it，常用作形式主语，放在句首，代替后移的真正主语：不定式短语、动名词短语或that从句。
It is necessary to take a walk every day. 每天散散步是很必要的。（it是形式主语，真正主语是不定式短语to take a walk every day）
It is no use crying over spilt milk. 牛奶洒了，哭也没用。（it是形式主语，真正主语是动名词短语crying over spilt milk）
It is a great pleasure that you have come to the party. 你来参加晚会，真是太好了。（it是形式主语，真正主语是that you have come to the party）
② 无人称代词it常用作形式宾语，代替后移的真正宾语：不定式或that从句。
I found it difficult to get the work done on time. 我发现很难按时完成这项工作。（it是形式宾语，真正宾语是不定式短语to get the work done on time）
I think it best that you should stay here. 我认为你待在这里最好。（it是形式宾语，真正宾语是that从句：that you should stay here）
③ 无人称代词it，可用于强调，结构为：It is+被强调的成分+that，被强调的可以是主语、宾语或状语。要注意的是，不论强调的是什么成分，不论是人、物、时间状语、地点状语或原因状语等，都要用that一词。比较下面两种结构：
It is…that+谓语+其他成分（强调主语时，直接用that作主语）
It is…that+句子（强调其他成分时，that后要加句子）
Li Ming told me the news yesterday. 李明昨天告诉了我那个消息。（非强调）
It was Li Ming that told me the news yesterday. 昨天告诉我那个消息的是李明。（强调结构，强调主语Li Ming）
He bought a blue pen this morning. 今天上午他买了一支蓝钢笔。（非强调）
It was a blue pen that he bought this morning. 今天上午他买的是一支蓝钢笔。（强调结构，强调宾语a blue pen）
He left on Sunday. 他星期天离开的。（非强调）
It was on Sunday that he left.
他是在星期天离开的。（强调结构，强调时间状语on Sunday）
It was on Sunday when he left.
The train arrived at the town during the night. 火车在夜间到达这座小城。（非强调）
It was during the night that the train arrived at the town.
火车是在夜间到达这座小城的。（强调结构，强调时间状语during the night）
It was during the night when the train arrived at the town.
He was born in this room. 他在这个房间里出生。（非强调）
It is in this room that he was born.
他就是在这个房间里出生的。（强调结构，强调地点状语in this room）
It is in this room where he was born.
He didn't come because it rained. 因为天下雨，他没有来。（非强调）
It was because it rained that he didn't come.
（强调结构，强调原因状语because it rained）
It was because it rained why he didn't come.
提示
①被强调的如果是指人的主语或宾语，有时可用who或whom代替that。
It is she who is wrong. 是她错了。
It is she that is wrong.
②注意下面强调句式的疑问句形式：
Is it that John often comes to school late that makes the teacher angry？是不是约翰经常上学迟到使老师生气的？
Was it at midnight that you heard the strange sound？你是不是在半夜听到那个奇怪的声音的？
Why was it that he sold the house？他卖了房子到底是为什么？
Where was it that they made a date for the first time？他们是在哪里第一次约会的？
