1)It + is/was + 被强调部分 + that/which/who/whom/whose + 句子的其他成分：

　　在这一结构中，如果被强调部分是人，用"that"，“who”，“whom”;如果被强调部分是物，用"that"或“which";强调状语时，只能用"that"，不能用"when"，“where” 和"why";强调的主语是复数，主句的谓语动词也得用单数。

　　It was uncle Bill、whose telephone number I lost.

　　It was we that/who arrived there first.

　　It was because it rained heavily that they didn’t go outing.

　　③作表语的形容词不能用于强调句式。

　　误：It is beautiful that Helen is.

　　④“No matter”+“关系代词/关系副词”加强语气：

　　Tom is absolutely right in doing this job.

　　This is just the word the author uses in his article.

　　He is nothing if not careful.(=He is very careful.)

　　They are the truest of friends.

　　The very act stepping on this soil was for me a far greater adventure.

　　The newspaper reporters got excited at the very sight of the Nobel Prize Winner.

　　It is beautiful song that Helen is singing.

　　2)“It+情态动词+be+被强调部分+that+…”表示强调：

　　It must be Mike that is listening to the music.

　　It might have been John who was in the traffic jam.

　　It would have been at that time that he went to live in London.

　　3)“It is/was + not until+被强调部分+that+…”表示强调：

　　It was not until dark that she realized it was too late to go shopping.、

　　It is not until the radiant energy falls upon matter that it becomes heat energy.

　　Who was it that interviewed Betty.

　　Where was it that you were born?

　　Could it be at the meeting that I met the，teacher?

　　He told me that it was because he was ill that they decided to return.

　　[注]在疑问句中，当宾语是"them"时，强调时应改为"those"

　　Did the professor regard them such contempt? →

　　Was it those that the professor regarded with such contempt?

　　5)对否定句中的某部分强调时，要注意"not"的前移：

　　6)在“It is/was……”之后可用“肯定+否定”或“否定+肯定”形式，以加强对比含义。

　　It is you not me who should be blamed.

　　It wasn't a knife but a dagger that I saw under the desk.

　　It was due to luck rather than judgment that the driver succeeded in avoiding an accident.