It isIwhoama teacher.
Itisthey who often help me with my lessons.
3)在强调时间、地点、原因或方式状语时，不能用when，where，why或 how ，而要用that 。如：
It was onlywhen I reread his poems recentlythat I began to appreciate their beauty.
It wasin the housethat the murder happened.
It wasbecause her mother was illthat she didn't go with us.
4强调句型：It is(was) not until ...that... 注意此时从句中的谓语动词要用肯定式。如：
It was not until 12 o'clock last night that my fathercamehome.
It was not until she took off her dark glasses that I realized shewasa famous film star.
5)原句的谓语动词如果是现在或将来的各种时态，用Itis…that (who)…;如果原句谓语动词是过去各种时态，则用Itwas… that(who)…
Did this happen in Beijing?
Was it in Beijing that this happened?
7)特殊疑问句中只有疑问词可以强调，其强调结构是“疑问词+is (was) it that...? " 如：
Where were you born?
Where was it that you were born?
8)强调句型容易和句型It is/was+名词+that名词从句混淆。如果把构成强调句型结构的词It is (was) … that(who)… 去掉，被强调部分归位后，应该能够形成一个完整 的句子(这也是判断是否是强调句型的方法)。但后者的It is/was…that 是不可去掉的，否则that前的名词就找不到位置，原句也不再成立，如下面这个句子如去掉It is/was…that就不再完整：
It was the rule of the school that the pupils should wear their school uniforms.
强调句型还容易跟It is/was+形容词+that名词从句这一句型混淆。如：It is clear (obvious, true, possible, certain....) that ..... 该句型中it 是形式主语，真正的主语是that 引导的主语从句，常译为”清楚(显然, 真的, 肯定…)”是主语从句最常见的一种结构。
It is very clear that he’s round and tall like a tree.
That he’s round and tall like a tree is very clear.
He told me that it was because he was late for class that he was punished.
I really can’t remember where it was that I first met the man.
It may be my bike that he is riding.
It must have been the manager that spoke to you.
Whom was it that Mr. Smith saw in the park yesterday?
Why is it that silver is not widely used as a conductor?
What a beautiful picture it is that you have drawn!
Was it Bill, who plays football well, that helped the blind man cross the road?
It was in the school, where(or：in which) I once studied, that we hold a party.
Was it in the house, which we visited last year,that the murder happened?
It was in the park that he met an old friend yesterday.(虽然强调的是地点，但不能用where。)
It is Mary and Tom who often do good deeds.
例4 (2014·湖南卷) It’s not doing the things we like， but liking the things we have to do that make life happy.
解析 make→makes。句意：不是做我们喜欢的事情，而是去喜欢我们必须做的事情才能让人生幸福。主语not doing the things we like， but liking the things we have to do是被强调部分， 应看作单数。
4.强调句型的时态常见的有两种：一般现在时和一般过去时。即it is ... that/who ...和it was ... that/who ...。如：
It was the way he asked that really upset me.
It was for this reason that he left that school.
It was in this way that he solved the problem.
It was only when I reread his poems that I began to appreciate their beauty.
It was on July 7th 1975 when he was born that his father died.
例5 Could it be in the restaurant where you had dinner with me yesterday where you lost your handbag?
解析 将第二个where改为that。that与前边的could it be共同构成强调句。本题解题的关键在于搞清楚句子中两个where究竟哪一个引导的是定语从句。本句的应意为：你有可能正是在你昨天和我吃饭的那家馆子丢失的手袋吗?针对这种从句套从句的情况，同学们一定要仔细辨别。
Was it during the Second World War that he died? (一般疑问句)
When was it that the sports meeting began? (特殊疑问句)
It was not Tom that stole the book. (否定句)
Wasn’t it he that had made a mistake? (否定疑问句)
例6 (2014·四川卷) Was it because Jack came late for school ________ Mr. Smith got angry?
It might be him that you met yesterday.
例7 (2016·浙江卷·阅读理解C) For example， it may only be through repeated experiments， evidence gathering， and finally overturning a theory， that a baby will come to accept the idea that other people can have different views and desires from what he or she has.
解析 句意：例如，它可能只是通过反复实验，收集证据，并最终推翻一个理论——一个婴儿会接受其他人可以和他/她有不同的意见和愿望的想法。这句话使用强调句，强调的是through repeated experiments， evidence gathering， and finally overturning a theory，这部分比较长，同学们可能没有注意这个句式。主干部分中idea后面是同位语从句，from后面还有宾语从句。