一、引言
在看學生的雅思寫作文章過程中，總會看到這樣的文字，“College graduates are difficult to find jobs. ”，“Parents realise the needs of their children is extremely important. ”，“Students cannot focus on their study because of tiredness is a fact. ”， “Clearly, rush hours emerges in the early morning as well as early evening which is most busy in a day as a whole in London.” 這幾個句子，雖然長短不一，結構不同，話題各異，但是，學生對形式主語it的駕馭能力的欠缺，是可見一斑的。
二、形式主語
（一）什麼是形式主語
作為形式主語的it並無實際語義，是為滿足語法上的需要，避免句子頭重腳輕，它代替的是句子的邏輯主語。
（二）形式主語it所在的句型類別
1、作不定式的形式主語
（1）句型
It is + a pity/a pleasure + to do sth.
It is + wrong/right/wise/cruel/naughty/selfish + of sb. + to do sth.
It is + necessary/hard/important/difficult/possible/common + for sb. + to do sth.
（2）雅思範文寫作實例
A. Beyond this, it is also of paramount importance to use theaters and museums as the “social classroom" of culture and history education.
B. I think it is by no means pointless in any way to try to keep traditions alive with technology (Cambridge;3,;P162,;Task;2)
C. It is difficult to say who has the rightto judge whether children working is “wrong” or “valuable”. (Cambridge;3,;P164,;Task;2)
D. it is important to remember that need to develop skills other than intellectual ones and …(Cambridge;3,;P168,;Task;2)
E. Finally, I think that it is also important to remember that children need to relax as well as work. (Cambridge;3,;P168,;Task;2)
F. Because people interpret happiness for themselves in so many different ways it is difficult to give and definition that is true for everyone.(Cambridge;4,;P165,;Task;2)
G. It is quite common these days for young people in many countries to have a break for studying after graduation from high school.(Cambridge;5,;P165,;Task;2)
H. They may think that it is better to continue in a particular job or to do sth completely different from a university course. (Cambridge;5,;P165,;Task;2)
據本人統計，劍橋官方的雅思真題（劍3—劍8）幾乎每一篇Task2考官範文中，都有所使用，甚至在有的文章中出現三次之多。