Do you know what this is?
What do you want?
you-know-what; whatsit; what's-his-name
Used as a placeholder when the speaker cannot recall or prefers not to say the actual word; covers both things and people.
Um, you know, that thing, pass it to me.
Yesterday I met what's-his-name.
(not) at all; (not) in the slightest
Used with a negative predicate to emphasize a complete lack or absence; often in the pattern 何も〜ない or 何の〜もない.
There is no problem at all.
It's of no use whatsoever.
Interjection showing anger or irritation, often used to scold or protest.
Hey, don't mess around!
oh, no (it's fine); why (it's nothing)
Interjection used to dismiss someone's worries or concerns, often with a reassuring tone.
Oh, don't worry about it.
What kind of book is this?
There was no explanation at all.
What's with that attitude!
What did he say?
Why did you do such a thing?
なに is the neutral question word for 'what', while 何だ(なんだ) is an interjection used alone to show surprise or annoyance rather than to ask a question.
in various ways; one way or another; in many ways
(not) one; (not) a single
something; some kind of · for some reason; somehow
please; kindly; I beg of you · by all means; without fail
important person; someone (sarcastic) · absolutely; certainly; to be sure
in any case; anyway; after all; you see
casual; nonchalant; unconcerned · ordinary; everyday; unremarkable
in any case; anyway; after all · because; since; as you know
some; any; a little; of some kind · please; kindly · anyway; at any rate; after all
what kind of thing; what · anything (else); nothing (but)
what the?; what's this?; what's going on?
some; a certain amount · a certain person; Mr. So-and-so · I; me
what; which things · so-and-so; such and such; something or other · what?; wait; hang on · well, well; let's see · no; oh (not at all); please; there, there
something; some; any · somehow; for some reason · what (do you mean)?; so what?
what?; huh? · why; for what reason
what nationality
anyone; any person; whoever
what name; what's-his-name
what shape?; what type?; which model? · which blood group?
who; what kind of person
what star sign; what constellation