一体
(What) the heck?, (Who) in the world?, (Where) on earth?, (How many) f*ing...
Structure
Explanation
To add a strong sense of surprise, confusion, or disbelief to a question, the adverb 一体 is used with interrogative words like 'what', 'why', or 'how'. You will commonly see いったい written in both kanji and hiragana.
いったい is typically placed at the start of a question, preceding the part that the speaker finds confusing or incredible.
- 一体外で何の音がしたんだ！What on earth was that noise outside?
- このルールは一体どういう意味だ。What in the world does this rule mean?
The literal definition of いったい is 'one unit' or 'in the first place'. Consequently, when used in questions, いったい carries the nuance of demanding a single, coherent explanation, similar to asking 'fundamentally, what is (A)?' or 'getting to the bottom of it, what is (A)?'.
- 一体なんでパーティーは中止になったの？Can you explain to me why on earth the party was called off?
- 一体どうしてあのいい仕事を辞めたの？I just don't get it, why would you quit such a good job?
Fun Fact
Stemming from its literal meaning of 'one unit' or 'as one', 一体 can also mean 'on the whole' or 'generally' when followed by the particle に, forming 一体に. This usage is now quite rare, mainly because the interrogative function of 一体 to express bewilderment is far more prevalent.
- 日本の食べ物は一体に美味しいです。Japanese food is, on the whole, delicious.
Examples
一体どこでこんなものを見つけてきたんだ？
Where on earth did you find something like this?
彼は一体なぜ電話に出ないんだ！
Why the heck isn't he answering his phone?!
こんな大きな家に一体誰が住んでいるのだろうか。
I wonder who the heck lives in a huge house like this.
一体何を言っているのか、さっぱり分からない。
I have no idea what on earth you're talking about.
一体どうしてこんなことになったんだ？
How on earth did things end up like this?
このレストランの会計、一体いくらになるんだろう…
I wonder how freaking much the bill at this restaurant is going to be...
彼女は一体どういう考えで仕事を辞めたんだろう。
What on earth was she thinking, quitting her job?
バスは一体いつになったら来るんだよ。
When the heck is the bus going to get here?
真夜中に聞こえるあの音は、一体何だろう。
What on earth could that sound be in the middle of the night?
一体いくつケーキを食べるつもりなの？
How many freaking cakes are you planning to eat?
このひどい成績は一体どういうことなの？
What on earth is the meaning of these terrible grades?
あの会社は一体何を作っているのだろう。
I wonder what on earth that company even makes.