suppose的用法请问suppose有什么语法知识吗?had been supposed to和was supposed to有什么语法区别吗 是不是在一定的句式中有规定的用法？不仅仅是时态问题？

suppose如何用
suppose的基本意思是“猜想；以为；假定”，但在具体的语言环境中意义不止于此，其用法如下：
1. suppose + that 从句，表示“猜测；假定”。如：
I suppose that you are right. 我想你是对的。
You can suppose that A equals B. 你可以假定A等于B。
2. suppose +名词 / 代词 + to be...，表示“认为……是……”。如：
Many people suppose him to be over 50. 许多人认为他已经50多岁了。
3. suppose用于祈使句中，表示“让……”。如：
Suppose we go for a swim. (= Let's go for a swim.) 让我们去游泳吧。
be supposed to 的用法
用法一： be supposed to... 其中to是动词不定式符号，不是介词，其后要跟动词原形。当be supposed
to... 的主语是“人” 时，意为“应该……
”；“被期望……”，它可以用来表示劝告、建议、义务、责任等，相当于情态动词should。如：
Everyone is supposed to wear a seat-belt in the car.
每个人在汽车里都应该系安全带。
Teachers are supposed to treat all the students alike.
老师应该对所有的学生一视同仁。
用法：当be supposed to... 的主语是“物”时，它表示“本应；本该”，用于表示“某事本应该发生而没有发生”。如：
The new laws are supposed to prevent crime. 这些新法令本应该起到防止犯罪的作用。
The train was supposed to arrive half an hour ago. 火车本应在半小时之前到达。
用法三： be supposed to后面接“have + 过去分词”时，表示“本应该做某事而没做”。如：
You are supposed to have handed in your homework by now.
现在你应该已经把作业交上来了。
He is supposed to have arrived an hour ago. 他应该一小时前就到了。
用法四： be supposed to... 的否定结构为be not supposed
to...,它常用于口语中，意为“不被许可；不应当”。如：
She was not supposed to be angry about that. 她本不该为那件事而生气的。
You are not supposed to smoke on the bus. 你不应该在公共汽车上吸烟。

had been supposed to和was supposed to主要是时态方面的区别,前者为过去完成时,后者为一般过去时.另外,前者有时还可表示“本来应该”,相当于was supposed to have done.
关于suppose的用法,本人在金盾出版社出版的《英语常用词多用途词典》上查到了以下用法,本来是摘录下来自己和的,现与你分享：
1.其后习惯上不接带疑问词的宾语从句,遇此情况,将疑问词移到主句句首：
Where do you suppose he has gone?你估计他去哪里了呢?
Who do you suppose has stolen the money?你认为是谁偷了这钱呢?
2.其后通常不直接跟不定式作宾语,遇此情况可改为宾语从句,如：
通常不说：He supposed to have left his umbrella in the bus.
可改为：He supposed that he had left his umbrella in the bus.他以为把雨伞忘在公共汽车上了.
3.后接不定式作宾语补足语时,不定式通常为to be.如：
I supposed him to be about forty.=I supposed that he was about forty.我估计他大约40岁.
若是to be之外的其他动词,则通常为完成式或进行式.如：
He was supposed to have left for home.大家以为已动身回家了.
4.有时可用于引导条件状语从句,相当于连词if,但此时与之相对应的主句通常(但不绝对)为疑问句.如：
Suppose he doesn’t agree,what shall we do?假如他不同意,那怎么办?
这样用的suppose有时还可用于虚拟语气.如：
Suppose you were given a chance to study in America,would you accept?假如给你一个到美国学习的机会,你会接受吗?
5.be supposed to do sth为习语,表示“应该(理应)做某事”.如：
They are supposed to arrive before dark.他们应该在天黑 前到.
Everybody knows,but nobody is supposed to know.本来谁也 不该知道这事,但人人都知道了.
注：其中的不定式有时可能是进行式或完成式.如：
He’s supposed to be doing his homework at home now.他现在应该在家里做作业.
He is not supposed to have left the hospital so soon.他本不该这么早就出院的.
另外,现在分词形式的supposing可用作conj.,表示“假如”,如：
Supposing he does not come,shall we go without him?如果他不来,是不是不带他去?/
Supposing he can’t come,who will do the work?如果他不来,谁来干这工作?
这样用的supposing与if用法相似,用以引导条件状语从句,但与之相对应的主句通常(但不绝对)为疑问句.有时还可用于虚拟语气.如：
Supposing there was a war,what would you do?假如发生战争,你怎么办?
Supposing you fell in love with your boss,what would you do?假定你爱上了你的老板,你会怎么办?
注：suppose也有类似用法：Suppose [Supposing] we miss the train,what shall we do?假如我们误了火车,我们将怎么办?