Is the phrase "Because of what?" a sentence fragment?

It seems like a fragment to me; it's an incomplete thought- or am I wrong about this?

I would love it so much if someone could provide an online source, but it isn't absolutely necessary.

Thank you!

2014-03-30T22:41:49Z

OK, so it is bad grammar, but ok to say colloquially. Thank you!

Actually, I completely messed up this question... I *meant* to ask if "Because what?" is a fragment/bad grammar.

2014-03-30T22:44:00Z

Ooops! Did you say *grammatically correct* omission of context?
I thought an ellipsis was automaticaly grammatically *incorrect*?

2014-03-30T23:29:22Z

OK, never mind my last question. I just did some reading about 'Elliptical Clauses' and learned that an ellipsis is considered acceptable.

But, "Because what?" and "Because of what?" didn't fall into any of the elliptical clause categories.

Anonymous2014-03-29T12:31:06Z

Favorite Answer

It's fine.

Whether something's a "complete thought" isn't a reliable rule for deciding whether something's a sentence. It's an idea teachers invented as a rule of thumb to avoid the need for grammatical analysis or usage evidence.

Utterances like this can generally be viewed as ellipsis (grammatically correct omission of context) of longer forms: "Because of what?" = "Because of what [did this happen]?".