asking what's the difference / what the difference is

Hi, I always have trouble with this:

It's like asking what's the difference between the sun and the moon.
It's like asking what the difference is between the sun and the moon.
It's like asking what the difference between the sun and the moon is.

Could someone comment on them? Thanks.

Both three seem to be correct to me.

<<Both three seem to be correct to me. >>

Lol, "Both three"?

Yes, all three are correct. You have flexibility here in which you prefer to use. Isn't English great!

Yes, English is somewhat flexible, but since it has a more rigid word order compared to my native tongue I tend to use prefixed patters so I can avoid mistakes despite I could play a little more with word order without speaking incorrectly. For example, in this case it's not a question really so I would use Subject+Verb+ Complements, hence: What the difference is between ...

No: the 1st one is incorrect, unless you put quotation marks around the "what's the difference" to show it is a quotation rather than an indirect question. The failure to construct indirect questions correctly is a glaring sign of an intermediate learner (or someone who watches Beavis and Butthead all day).

It's like

Where is he? but
Where's he at? (in dialects that use it)

Where's he? sound strange.

<< The failure to construct indirect questions correctly is a glaring sign of an intermediate learner >>

Actually, all three sound like something a native speaker would reasonably say. I do think that the first one is colloquial at best, but it is common.

I prefer the third one, myself. I think "between X and Y" should go with the word it is modifying, which is "difference".

- Kef

Wow, the thrid option places the verb at the end, I wouldn't remember the verb after so many words.

They're all correct but, actually, the third one sounds a bit pompous to me, I would never say that unless it was a formal situation.
The second one I somehow can't picture myself saying it, dunno why.
I would definitely say the first one, no doubt about it.

The 1st one is actually grammatically incorrect, but may be heard. It depends if you want to copy grammatically incorrect English as used in the wild or not.