It was nothing.
Nani de mo nai yo.
what; how many; you-know-what; that; whatsit; what's the expression; what do you call them; what?; hey!
indicates location of action; at; in; indicates time of action; indicates means of action; cause of effect; by; and then; so; indicates continuing action; indicates certainty, emphasis, etc.
too; also; in addition; as well; (not) either (in a negative sentence); both A and B; A as well as B; neither A nor B (in a negative sentence); even; as much as; as many as; as far as; as long as; no less than; no fewer than; even if; even though; although; in spite of; further; more; again; another; the other
not; emphatic suffix
indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!
Readings: カ、 なに、 なん、 なに-、 なん-