1.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。
用法二：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
2.be expected to do 和 be supposed to do 区别
be supposed to do是被期望或要求,应该.相对于be expected to do 主观性强一些.它相当于should的这个用法
是有希望做（成）……
expect在朗文的第一词条即为：预料、期待。
例：They are expected to make an announcement later on today.(预料他们今天晚些时候会宣布一项通告)
再次例句中，be expected to do意为预料，表示一种可能性
再如：She is expected to be a good doctor.（他有希望成为一名好医生)
3.expect 用法
请读下面的句子，注意expect的用法。
1. I expect a snowstorm.
我预计会有一场暴风雪。
2. The old man is expecting his daughter’s visit. 21世纪教育网版权所有
这个老人盼望着他女儿的到访。
3. I expect to get a birthday present from my dad. 21*cnjy*com[来源:学科网]
我期待着收到一件来自父亲的礼物。
4. Do you expect him to teach you English?
你希望他教你英语吗？
5. I didn’t expect that you would get there so soon.
我没想到你会这么快就到达那里了。
【及时归纳】 expect是及物动词，意为“预料，盼望”，它有以下常见用法：[来源:Zxxk.Com]
1. expect + n. / pron. 预计……可能发生；期待某人或某物
2. expect + to do sth. 料想做某事
3. expect sb. to do sth. 期望某人做某事
4. expect + 从句 预计 / 料想……
