聚焦“It is + adj.（+ for /of...）+to do sth”句型

沈曉芳

形容詞常用來修飾名詞或代詞，表示人或物的特征、性質和狀態，在句中可以作表語或定語。本文我們重點學習三個與形容詞有關的句型。

句型一：It is + adj. + for sb to do sth

該句型中的形容詞多用來表示動詞不定式所具備的特征或客觀情況，意為“對某人來說做某事是……的”。這類形容詞有cheap， dangerous， difficult， easy， exciting， expensive， important， interesting， necessary， possible， useful， wonderful等。如：

It is very dangerous for children to cross the busy street.

對孩子們來說，穿過繁忙的街道很危險。

It’s necessary for you to choose that job.

你選擇那份工作是有必要的。

句型二：It is + adj. + of sb to do sth

該句型中的形容詞多用來描述人的性格或品質等，意為“某人做某事真是太……了”。這類形容詞有brave， careless， clever， foolish， good， helpful， honest， kind， nice， polite， silly， wrong等。如：

It’s careless of you to lose so many things.

你丟失這么多東西，真是太粗心了。

It’s very nice of him to offer me a seat.

他給我讓座，真是太好了。

句型三：It is + adj. + to do sth

該句型中的形容詞多用來表達對某一件事的看法，意為“做某事是……的”。當敘述眾所周知的事情或沒有必要表示出動詞不定式的邏輯主語時，通常不需要加for / of sb。如：

It is useful to remember lots of words before the exams.

考試前記住很多單詞是有用的。

It is impolite to speak loudly in the library.

在圖書館大聲說話是不禮貌的。

真題回放

1. —（2019·四川·涼山）Is it necessary ______ us ______ some photos before saving the old man？

—Yes， it is. We can protect ourselves if we do so.

A. of; taking B. for; taking

C. of; to take D. for; to take

【答案與解析】D. 句意：“——對我們來說，在救助老人之前有必要拍些照片嗎？——是的，有必要。如果我們這樣做了，就可以保護自己。”本題考查“It is + adj. + for sb to do sth”句型。故選D。

2. （2019·內蒙古·呼和浩特）It is wise ______ Linda to make up her mind ______ to play an instrument.

A. for; learning B. for; to learn

C. of; learning D. of; to learn

【答案與解析】D. 句意：“琳達下決心學習演奏樂器是明智的。”本題考查“It is + adj. + of sb to do sth”句型以及固定搭配make up one’s mind，后面常跟不定式作賓語。故選D。

◎ 鞏固練習

從A、B、C、D中選出可以填入空白處的最佳答案。

1. It is very important__________us__________enough water every day.

A. for; to drink B. for; drinking

C. of; to drink D. of; drinking

2. When you’re having meals in a western restaurant， it is important__________with your mouth full.

A. to speak B. don’t speak

C. not speak D. not to speak

3. It isn’t wise__________teenagers to be crazy about Korean stars. It is necessary__________them to learn more about Chinese culture.

A. for; of B. of; for

C. of; of D. for; for

4. —It is really__________of you to offer me such useful advice.

—It’s my pleasure. I hope the advice will help you.

A. kind B. brave

C. careless D. generous

5. —Do you think__________is dangerous__________drivers to drive after drinking？

—Of course. That’s the cause of many traffic accidents.

A. that; of B. this; for

C. it; for D. it; of