be supposed to do的用法

王嵩

be supposed to do意為“應該，被期望，理應做……”。用來表示根據規定或傳統習慣人們不得不做，或期待發生的事。時態、人稱和句式的變化在be上體現，to為不定式符號，后接動詞原形。

1. be supposed to do的肯定句式，例如：

Everyone is supposed to wear a seat-belt in the car.

每個人在小汽車里都應該系好安全帶。

You’re supposed to start work at 8：30 every morning.

你應該每天早晨8點半開始工作。

They are supposed to shake hands. 他們應該握手。

2. be supposed to do的疑問句式，要將be的相應形式提到主語前。例如：

Is he supposed to get there at five？ 他應該在5點鐘到嗎？

Was Lucy supposed to speak Chinese like that？ 露西應該像那樣說漢語嗎？

What are you supposed to do？ 你們應該做什么？

When were you supposed to arrive？ 你們應該什么時候到？

3. be supposed to do的否定句式，即在be動詞后加否定副詞not，此時相當于be not allowed to do，意為“不被許可，不應該”。例如：

You are not supposed to smoke here. 你不應該在這里抽煙。

We are not supposed to play football in the street. 我們不應該在大街上踢足球。

It is a secret still. I am not supposed to say. 這還是個秘密，我不能說出來。

4. suppose sb. to be有“某人/某事認為某人如何”的意思。其主動形式為“suppose sb. to be+形容詞/名詞”。例如：

All the classmates suppose him to be stupid.（=He is supposed to be stupid by all the classmates.）But in fact， he is a good student.

所有同學都認為他愚蠢，事實上他是一個好學生。

People in old times supposed the earth to be flat.（=The earth was supposed to be flat by people in old times.）But now we know it is round.

古時候人們認為地球是平的，但我們現在知道它是圓的。

We suppose her to be an actress.=She is supposed to be an actress.

我們認為她是個女演員。

5. suppose作動詞，意為“認為，猜想，想象”，suppose后接從句和to be作賓語。例如：

I suppose he is not yet thirty. 我猜他還不到30歲。

—Do you suppose it is going to rain？ 你認為會下雨嗎？

—I suppose so. 我想會吧。

We all suppose Jenny to be the best student in our class.

我們都認為珍妮是我們班里最好的學生。

注意：作此意講時，suppose可用于簡略答語中，常用于簡略答語中的動詞還有think，believe，expect，hope等。suppose引導的賓語從句如果是特殊問句，疑問詞應提前。例如：

Who do you suppose is coming with Mr Yang？

你認為誰會和楊老師一塊兒來？

6. suppose作動詞時還有“假定，假使”之意，后接從句。suppose此時可當作if來用，往往表達想象中的條件。例如：

Suppose （that）it rains， what shall we do？

假如下雨我們怎么辦？

Let’s suppose （that）he is telling a lie.

且假定他在說謊吧。