JLPT N4
てしまう
End up doing / Completely do
Structure
Verb て-form しまう
How it works
This grammar point expresses two main ideas: that an action has been completely finished, or that an action happened accidentally with a sense of regret or irony. In casual speech, 〜てしまう often contracts to 〜ちゃう, and 〜でしまう becomes 〜じゃう.
Examples
宿題を全部やってしまいました。
I finished all of my homework completely.
電車の中に傘を忘れてしまいました。
I accidentally left my umbrella on the train.
ケーキを一人で食べてしまった。
I ended up eating the cake all by myself.
Common mistakes
Mixing up the nuance; remember that 'teshimau' is rarely used for positive, intentional achievements unless focusing on the 'total completeness' of the task.
Tip
To sound more natural in daily conversation, practice using 'chau' (e.g., 'tabechatta' instead of 'tabete shimatta') as this is how native speakers use it most frequently.
More JLPT N4 grammar
See てしまう in real Japanese
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