首先我们来看下be expected to do和be supposed to do的大致意思：
be expected to do：词性为动词短语，be expected to do是一个被动形式的表述，其中的to do是不定式的形式，表示被期望去做某事。
be supposed to do：词性为动词短语，be supposed to do是一个被动形式的表述，其中的to do是不定式的形式，表示应该去做某事。
通过下面的表格我们了解下be expected to do和be supposed to do的含义、发音和用法
接下来让我们看下be expected to do和be supposed to do的用法区别：
1.语义区别：be expected to do强调被期望去做某事，而be supposed to do强调应该去做某事。
例子：
- I am expected to write a report.
(我被期望写个报告。)
- You are supposed to exercise every day.
(你应该每天锻炼身体。)
2.态度区别：be expected to do表示一种客观的期望，而be supposed to do表示一种主观的应该。
例子：
- She is expected to complete the task successfully.
(她被期望顺利完成任务。)
- We are supposed to respect each other.
(我们应该相互尊重。)
3.强制性区别：be expected to do没有明显的强制性，而be supposed to do含有一定的强制或义务。
例子：
- Employees are expected to complete their work on time.
(员工被期望按时完成工作。)
- Students are supposed to follow the school rules.
(学生应该遵守校规。)
4.预期区别：be expected to do暗示某种预期结果，而be supposed to do强调某种预期行为。
例子：
- He is expected to pass the exam.
(他被期望通过考试。)
- You are supposed to speak at the meeting.
(你应该在会议上发言。)