1.一般疑问句的强调,强调疑问部分

It was he that/who gave you that fish

Was it he that/who gave you fish? //只是将be提前

2.特殊疑问句的强调(特殊疑问词放在句首)强调疑问词

When and where were you born

When and where was it that you were born?

// 特殊疑问词放在句首 + be it that 疑问句的语序

What was it that made you so sad?

why is it that you want to change your mind

where was it that you met him?

what is it that(on earth) you want me to say? // what do you want met to say

3.双重否定表示强调

It is not uncommon(很常见) that different persons entertain theselves in different ways

it is not unreleastic(很现实) tha most people live for money. // 太现实不过

I can't live without you.

// 例句

It was how the young man had learned(过去完成时态) five foreign languages(强调整个句子) that attracted the audiences interst.

people in the west make it  a rule buy Christmas presents for their relatives and friends.

it was playing computer games that cost the boy plenty of time (定语从句)that he ought to have spsent (in) doing his lessons.

(形式主语)it needs further discussion whether we'll build a library or not // 主语从句

it was the culture, rather than the language that   made it hard for him to adapt the new environment abroad.

was it on(介词短语,只能用that修饰) a lonely island that he was saved on month after the boat went down.

It was not until she got home that jennifer realized she had lost her keys

Who was it that saved the drowning girl

it is the ablility to do the job that matters not where you come from or what you are

it was in Shanghai that i saw that movie

where is it that he stay I don't know

It was three days later that she remembered (having left) leaving her (raincoat雨衣)umbrella  in the language Lab.(laboratory)