やってしまう
やってしまう
expression
to do completely; to go and do; to mess up
1.
to finish doing; to get done; to go ahead and do
やる plus the ～てしまう aspect marker. The neutral reading is completion: 'get the thing done', often with a sense of resolving to do it now rather than later.
宿題をやってしまおう。
Let's just finish the homework.
今日中にこの仕事をやってしまいたい。
I want to get this work done today.
面倒な書類は、早めにやってしまった方がいい。
It's better to get tedious paperwork out of the way early.
2.
to mess up; to blow it; to do something one regrets
The same form takes on a negative emotional reading depending on context, especially in the past tense (やってしまった): 'I did it (and now I regret it)'. Contracted to やっちゃう / やっちゃった in casual speech.
やってしまった！
I messed up!
緊張してまた同じミスをやってしまった。
I got nervous and made the same mistake again.
言ってはいけないことをつい口に出してやってしまった。
I let something I shouldn't have said slip out.
やる + the aspect marker ～てしまう. The two senses share one form but are usually clear from context — present/volitional usually means completion, past usually means regret.
CONTRACTIONS:
- やってしまう → やっちゃう (casual)
- やってしまった → やっちゃった (casual, the most common form of sense 2)
SIMILAR PATTERNS:
- 済ませる: to finish off; to get over with — focused on completion only, no regret reading
- ～切る: to do thoroughly to the end — full completion, no negative nuance
- しまう alone: same aspect marker after other verbs (食べてしまう, 忘れてしまう)