1、suppose 意为“认为，猜测”，后常接“宾语+宾语补足语”形式。suppose sb./sth. to have done 的结构。
例如：
They supposed the paper to have been lost during the war. 他们认为那个文件在战争期间丢失了。
The police arrested him because he was supposed to have killed the lady. 警察逮捕了他，认为他杀死了那位女士。
2、suppose 可用于“ be supposed +不定式”的结构。
be supposed to do sth. = should do sth. 意为“应该 / 理应做某事”，表示被期望或被要求(按规则、惯例)做某事。
例如：
We are supposed to help each other. 我们理应互相帮助。(要求)
You are supposed to hand in your papers before class is over. 希望你下课前交卷子。(期望)
3、suppose 可用过去完成时表示“未曾实现的愿望”。
例如：
We had supposed that we would be able to see more of Shanghai, but time didn't permit. 我们本打算能多看看上海，但时间却不允许了。
注意：与 suppose 这种用法相同的还有： hope, think, expect, mean, want, intend, plan (一些表示心理状态的动词)等。
4、suppose 可用于“ suppose + that (从句)”句型。
例如：
What makes you suppose (that) I'm against it? 你根据什么认为我反对这件事?
It was generally supposed that it would not happen again. 一般认为此事不会再发生。
5、suppose 可用于简略答语中，用 so 代替一个肯定的宾语从句;用 not 代替一个否定的宾语从句。
Do you suppose he'll fail to catch the train?你认为他会错过火车吗?
I suppose so./ I suppose not. (= I don't suppose so. )我想会的。 / 我想不会。
注意：与 suppose 这种用法相同的还有： think, believe, expect, imagine 等。但应注意 hope 和 be afraid 则不同于以上的用法。