He seems to do ../He seems to have done..../He seems to be doing ....的区别？

He seems to do ..他像是准备作某事
举例：He seems to watch TV.
他好像要去看电视。

He seems to have done..他好像已经做完某事
举例：He seems to have finished his homework.
他看起来已经做完家庭作业了。

He seems doing ...他像是正在作某事
举例：He seems having a good dream when I come into his room and see he sleep in bed.
当我走进他房间看他睡觉时他像是正在做一个美梦。

这三句话考查的都是seem to do（看上去像，好像）的用法，只是后面分别接的是天to do 不定式的不同时态的不同形式，第一句是一般式，第二句是完成式，第三句是现在进行式。
seem的用法
1.后面直接接名词，形容词等。
eg：He seemed an honest man.他好像是个诚实的人
= He seemed to be an honest man. 可以有这样的同义变化。
2.seem 的否定既可以在它的前面也可以在它的后面
eg: She does not seem to like you.
= She seems not to like you. 她好像不喜欢你。
3.seem 与引导代词it连用，表示“看来好像，似乎”
eg:It seems as if it is going to rain this evening.
4.seem 与人称代词I 连用，表示“感觉好像，似乎”
eg:I seem to have seen him somewhere before.
5.seem 后还可接that从句，like, as is ,as 等。

这是高中范围内涉及到的用法，我给小孩讲的话就是这些内容，希望对你有帮助。

He seems to do ..
他似乎做（并不是