〜てしまう
てしまう
expression
to end up doing, to completely do
1.
to end up doing (regret/unintended)
Indicates that an action was done unintentionally or with a sense of regret. Often implies the speaker wishes it hadn't happened.
2.
to completely do, to finish doing
Indicates completion of an action, emphasizing that it's done thoroughly or can't be undone.
Let's get the homework done (and be done with it).
Volitional: determination to complete
I want to finish the work completely.
Formation: て-form + しまう
FORMS (casual contractions):
Forms
- 〜てしまう (dictionary)
- 〜てしまった (past)
- 〜てしまいます (polite)
- 〜てしまいました (polite past)
Usage
- With negative actions: regret (壊してしまった = broke it, unfortunately)
- With deliberate actions: completion, getting it out of the way (片付けてしまった = got it all cleared away)
- With events outside one's control, often regret that something is over: 夏休みが終わってしまった (summer vacation is over, sadly)
- In volitional form: determination (やってしまおう = let's just do it)
The contracted forms (ちゃう/じゃう) are very common in casual speech.