What does it mean word for word?
The term 一体 (ittai) literally means "one body", but in this context, it functions as an intensive particle used to mean "on earth" or "the heck."
Which one should you use?
The phrase 何をしているの? is a neutral way to ask "what are you doing?", whereas adding 一体 shifts the meaning to "what on earth/the heck are you doing?" There are also several informal alternatives: 何してんの? is a standard informal way to ask "what are you doing?", 一体何やってるの? emphasizes surprise or curiosity and 何やってんの? is a common informal way to show astonishment or confusion.
Is there a formal and an informal way to say it?
For a more blunt, masculine or rough tone, you can use the informal variation 一体何をしてるんだ? which utilizes the contraction してる and ends with だ.
How does it change in a sentence?
At the end of the sentence, the particle の functions as a question marker that adds a tone of seeking an explanation or expressing mild surprise or irritation.
How do you pronounce it?
ittai nani o shite iru no?
Did you know?
- Using the formal version of this phrase with a superior in a Japanese company would be considered an extremely aggressive act of defiance, regardless of the polite grammar used.
- The verb やる (yaru) used in 何やってんの? can also mean 'to feed' or 'to give' when speaking to a social inferior or a pet. This versatility makes the word uniquely flexible in expressing both action and social hierarchy.
- While 'the heck' in English often signals annoyance, the Japanese 一体 (ittai) can actually be used to express a sense of deep, sincere wonder or amazement at something strange.
Examples in context
- 一体何をしているの？ittai nani o shite iru no?What the heck are you doing?
- 一体何をしているの？一人でそんな高いところへ。ittai nani o shite iru no? hitori de sonna takai tokoro e.What the heck are you doing? Going up such a high place all alone.
- 夜中に一体何をしているの？yonaka ni ittai nani o shite iru no?What the heck are you doing in the middle of the night?
Example conversation
Kenta finds Himari playing a loud instrument late at night.
- 健太 Kentaこんな時間に一体何をしているの？konna jikan ni ittai nani o shite iru no?What the heck are you doing at this hour?
- 陽葵 Himariあ、練習中だよ。a, renshuu chuu da yo.Oh, I'm practicing.
- 健太 Kentaすごくうるさいよ。sugoku urusai yo.It's really loud.
- 陽葵 Himariごめんね、気を付けるね。gomen ne, ki o tsukeru ne.Sorry, I'll be careful.
