一、结构分析 强调结构中的it is (was)that (who)为使一个非强调句变成强调句的结构词，在通常情况下，去掉它，句子依然是成立的这是判断一个句子是否为强调结构的重要标志。如下面这个句子是强调句，因为去掉it wasthat后思维导图

It was my mother who finally called the police. 最终报警的是我母亲。

→My mother finally called the police. 最终报警的是我母亲。

请看下面一句，空白处是填that还是其他的什么词？

It was ten o'clock _______ he returned home.

此处不能填that，因为若填that把它视为强调句，那么就可以去掉it was…that…而使句子结构完整，意思不变，事实上并非如此，因为我们是不能说Ten o'clock he returned home的，除非改为At ten o'clock he returned home才是正确的。

It was ten o'clock when he returned home. 他回家的时候已是10点钟了。

It was at ten o'clock that he returned home. 他是10点钟回家的。

It is not I who am angry. 发怒的不是我。(同时用现在时)

It was my two sisters who knew her best. 是我的两个姐妹最了解她。(同时用过去时)

It will not be you who will have to take the blame for this. 对此须受责难的将不是你。(同时用将来时)

It is Miss Williams who enjoyed reading novels as a pastime. 是威廉姆斯小姐以读小说来消遣。