be supposed to的用法
suppose的基本意思是“猜想；以為；假定”，但在具體的語言環(huán)境中意義不止于此，其用法如下：
1. suppose + that 從句，表示“猜測；假定”。如：
I suppose that you are right. 我想你是對的。
You can suppose that A equals B. 你可以假定A等于B。
- suppose +名詞 / 代詞 + to be...，表示“認為……是……”。如：
Many people suppose him to be over 50. 許多人認為他已經(jīng)50多歲了。
- suppose用于祈使句中，表示“讓……”。如：
Suppose we go for a swim. (= Let's go for a swim.) 讓我們?nèi)ビ斡景伞?/p>
be supposed to 的用法
用法一： be supposed to... 其中to是動詞不定式符號，不是介詞，其后要跟動詞原形。當be supposed to... 的主語是“人” 時，意為“應該…… ”；“被期望……”，它可以用來表示勸告、建議、義務(wù)、責任等，相當于情態(tài)動詞should。如：
Everyone is supposed to wear a seat-belt in the car.
每個人在汽車里都應該系安全帶。
Teachers are supposed to treat all the students alike.
老師應該對所有的學生一視同仁。
用法二：當be supposed to... 的主語是“物”時，它表示“本應；本該”，用于表示“某事本應該發(fā)生而沒有發(fā)生”。如：
The new laws are supposed to prevent crime. 這些新法令本應該起到防止犯罪的作用。
The train was supposed to arrive half an hour ago. 火車本應在半小時之前到達。
用法三： be supposed to后面接“have
- 過去分詞”時，表示“本應該做某事而沒做”。如：
You are supposed to have handed in your homework by now.
現(xiàn)在你應該已經(jīng)把作業(yè)交上來了。
He is supposed to have arrived an hour ago. 他應該一小時前就到了。
用法四： be supposed to... 的否定結(jié)構(gòu)為be
not supposed
to...,它常用于口語中，意為“不被許可；不應當”。如：
She was not supposed to be angry about that. 她本不該為那件事而生氣的。
You are not supposed to smoke on the bus. 你不應該在公共汽車上吸煙。
suppose的其他用法：
1．suppose ＋that 引導的賓語從句“假設(shè)，猜想，以為”。例如：
Let's suppose that you had a million dollars，how would you spend it?
假如你有一百萬美元，你怎么花呢?
I suppose that she'll be there today．
我想她今天能到那里。
I had supposed he had died years ago．
我原以為他幾年前就去世了。
2． 當suppose ＋that 引導的賓從變?yōu)榉穸ň鋾r，否定應前移，有此種用法的詞有think，believe， guess（猜想）等。例如：
I suppose that she will come to your party．
→ I don't suppose that she will come to your party．
我猜她不會來參加你的晚會。
I suppose that he will agree with you．
→ I suppose that he will agree with you．
3． 在表示同意或不同意別人的觀點時，常用“I suppose
so/ I don't suppose so”。
－－－ Will he be back this weekend?
他周末會回來嗎?
－－－ Yes， I suppose so．
我想他會回來。
