The correct usage and the context of construction 'all of smth.'.

[Weaver67]

Hello, teachers.

Let's imagine following situation.

Someone ask me a strange question about a favorite part of something whole. However, by my mind it's not only whole but holistic entity, so the question is quiet meaningless. So, I don't want to offend that person by direct pointing to, that's why I would like to answer more diplomatically but at the same time to drop a hint in a kind and an ironic manner.

For example:

Q: Which parts of a person's body do you like?
A: I like all of the parts, of course.

Is answer proper in context above? Is it correct?... Or I should answer like this: 'Of course I like all parts of the body'.
Which answer is more appropriate to the context?

Thanks a lot in advance.

[5jj]

It's not easy to answer your question, because, as you say, the original question is strange. I don't think it is possible to do what you want to do - So, I don't want to offend that person by direct pointing to, that's why I would like to answer more diplomatically but at the same time to drop a hint in a kind and an ironic manner.

Personally, I would probably say something like, "I've never thought about it. I don't see how you can 'prefer' one part of a body".

Of course some young people discuss which parts of the body of a member of the opposite sex attract their attention first (e.g. hair, face, chest/breasts, buttocks, legs), but that's a different situation.

[Weaver67]

It is very likely that you're right 5jj.
Maybe I should change the focus of the issue.
If it wasn't bound strongly to the context above... Were the both answers in my example semantically equivalent?

[Barb_D]

You will hear "all of the X" but when X is plural, I don't find the "of" necessary. I'm not prepared to say it's wrong, but "all the parts" sounds better to me than "all of the parts."

[Weaver67]

Thanks all for comments.
Yes, I agree. The variant without 'of' sounds better anyway. But I know that form 'all of X' is more applicable for some cases. I guess, there're a lot of such cases.

E.g. with pronouns:
"Those days all of us knew her well, except person standing just in front of me."
Here we denote a certain (relatively small) group of people.

...or with a noun phrase in plural

"Our classes lasted all of six weeks. "
Here we speak (probably ironically) about a small amount of time, as we considered.

What do you think about above? Is it correct? Are there another cases or contexts of application phrase 'all of '? What is the common meaing(semantic) of this phrase?