本文中，小編為大家整理了形式主語it的5種用法，快來看看吧！

it的5種用法

1、指代性it一般是指人稱代詞it，it作人稱代詞時可指代事物、動物、嬰兒、未知的人或一件事。

2、不定式作主語，It's my pleasure (to help you).

3、it做先行詞。

4、it做形式賓語。

5、引導(dǎo)強調(diào)句的it。

it做形式主語基本句型

1.It+be+形容詞+主語從句，如：It is?uncertain?whether?he?can?come?to?Jenny’s?birthday?party?or?not.

2.It+be+名詞詞組+主語從句，這類名詞有：a?fact,a?pity,a?shame,an?honour，a?question等，如：It’s?a?pity?that?you?missed?the?exciting?football?match.?It?remains?a?question?whether?he?will?come?or?not.

3.It+be+過去分詞+主語從句，這類過去分詞有：announced,believed,expected,hoped,decided,reported,said,?shown等，如：It?is?reported?that?16?people?were?killed?in?the?earthquake.?It?is?not?decided?who?will?give?the?operation?to?the?patient.

4.It+不及物動詞(seem,appear,happen等)+主語從句,這類不及物動詞有：appear,happen,seem等，如：It?seemed?that?he?didn’t?tell?the?truth.? It?happened?that?I?was?out?when?he?called.

5.It+be+形容詞+for sb.）+動詞不定式這類句型常用形容詞easy,difficult,hard,important,possible，wise等作表語，有時候為了強調(diào)不定式動作的執(zhí)行者，常在不定式前加for?sb，如：It’s?necessary?for?the?young?to?master?two?foreign?language.?It?is?unwise?to?give?the?children?whatever?they?want.? 這類形容詞有：easy,?difficult,?hard,?important,?possible，wise