如何使用形式主語

  形式主語是動詞不定式的一種,它也是邏輯主語, 可以把它歸類到邏輯主語的第一種用作賓語的不定式,用作目的狀語,用作結果狀語的不定式都是屬於不定式的大概念裡面的。以下是由小編整理關於形式主語的用法的內容,希望大家喜歡!

  形式主語的用法一:it作邏輯主語

  綜述

  形式主語it 作為形式主語的it並無實際語義,只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,概括起來會有如下情況:

  不定式作邏輯主語

  如:It is very kind of you to give me a hand in time.

  It is my pleasure to address the meeting.

  It was pretty hard for him to bring up the child on his own.

  從句作邏輯主語

  如:It so happened that the tickets were sold out.

  It is extremely obvious that she has been lying about her identity.

  It suddenly occurred to me that the message must have been hidden

  between the layers of the briefcase.

  動名詞短語作邏輯主語

  這類句子遠不如前面兩種出現率高,主要在***no good,waste,useless,no use,dangerous***等詞語的後面用

  如:It is no use reasoning with him.

  It is no good reading in dim light.

  作形式主語的代詞只能用it ,不能用that,this等詞。例如:

  1*** It is easier to lose friends than to make friends. 交朋友難而失去朋友比較容易。

  2*** It is important for modern young people to master at least two foreign languages. 掌握至少兩門外語對於當代年輕人來說是很重要的。

  以上兩句中的it是形式主語,真正的主語是後面的不定式短語。

  3*** It is considered no good reciting without understanding. 不理解的背誦被認為是沒有好處的。

  4*** It is no use crying over spilt milk. 覆水難收。

  以上兩句中的it是形式主語,真正的主語是V-ing形式。

  5*** It is a fact that English is being accepted as an international language.英語作為一門國際語言正日益為人們所接受,這是不爭的事實。***NMET,95***

  6*** It depends on the weather whether we will go. 我們去不去得看天氣行事。***其中的whether 不能換成if,因為if不能引導主語從句。***

  以上兩句中真正的主語是名詞性從句。

  形式主語的用法二:it作形式主語

  it 作形式主語,主要分為下列三種情況:不定式作主語、動名詞作主語 和 名詞從句作主語。具體分析如下:

  不定式作真正主語

  主要用於下列句型:

  ⒈It + is/was + adj./n. ***形容詞或名詞*** +to do sth.

  A. 名詞作表語。主要有a pity,a pleasure,an idea等。例如:

  In fact________is a hard job for the police to keep order in an important football match. ***2001上海高考題***

  A. this B. that

  C. there D. it ***答案為D***

  再如:It is a great pleasure to do this. 這樣做多好啊。

  It is a good idea to think this way. 這樣考慮問題是個好辦法。

  除be外,其他動詞也有跟名詞的情況。例如:

  It seems a pity to waste the food. 浪費這些食物真可惜。

  It requires efforts to master a foreign language. 掌握一門外語需要種種努力。

  B. 形容詞或形容詞短語作表語。分兩種情況:

  1*** 下列形容詞:kind,good,nice,clever,wrong,right,foolish,wise,unwise,stupid,rude,careless,cruel,brave,naughty,polite,selfish等詞作表語時,不定式前常可加一個由of引起的短語,來說明不定式指的是誰的情況。形容詞表示不定式邏輯主語的特徵,即形容詞用來描述不定式行為者的性格、品行等。例如:

  It was foolish of you to leave school.你中途退學,真是傻瓜。

  It was brave of her to speak out in public. 她能當眾大聲講話,真勇敢。

  這種of sb. to do sth. 句型,of 的賓語可以作句子的主語。上面兩個句子可以改寫為:

  You were foolish to leave school.

  She was brave to speak out in public.

  2*** 其他形容詞作表語,常見的形容詞有:necessary,hard, important,difficult,easy,possible,common等。例如:

  It is necessary to use a short-wave radio to pick up the programmes. 必須用短波收音機才能收到節目。

  如果要說明不定式表示的動作是誰做的,可以在不定式前加for + 名詞或代詞+ to do sth.***for 後的賓語不能作句子的主語***。名詞或代詞作不定式的邏輯主語,即表示不定式所指動作的執行者。在此句型中,形容詞只對不定式行為者作某種描述,而不涉及其品行。例如:

  It is not hard for one to do a bit of good. 對於一個人來說做點好事並不難。

  It,s common for leaves to fall from the trees in the fall. 秋天樹葉從樹上落下是件常事。

  需要注意的是:動詞不定式作主語,一般情況下用it作形式主語,而把動詞不定式***從句***放在後面。也可以直接用不定式作主語。例如:

  It is wrong to tell lies. = To tell lies is wrong. 撒謊是不對的。

  但在疑問句和感嘆句中,只能用it作形式主語。例如:

  Isn't it a good idea to have a walk around? 出去兜一圈難道不是一個好主意嗎?

  What a pleasure it is to work with you! 同你一起工作是多麼愉快啊!