Translation guide
How to express doing something completely, thoroughly, or to the end in Japanese. The best choice depends on whether you mean finishing a task, doing it exhaustively, or doing it with full effort.
To complete an action or process, often with a sense of finality.
Attach to the て-form of a verb to indicate completing an action, often with a nuance of finality or regret. Very common in spoken Japanese.
宿題を全部やってしまった。
I did all my homework completely.
この本を読んでしまおう。
Let's finish reading this book.
To accomplish or carry something through to the end, emphasizing effort and achievement.
彼は難しい仕事をやり遂げた。
He completely did the difficult task.
Formal term for completing a task or process, often used in business or technical contexts.
プロジェクトを完了しました。
We have completed the project.
To finish doing something, often used for tasks or activities. More formal than 終わる.
仕事を終えたら連絡します。
I'll contact you when I've finished the work.
To perform an action in a comprehensive, detailed, or exhaustive manner.
Adverb meaning 'thoroughly' or 'exhaustively'. Used with verbs to indicate doing something completely without leaving anything out.
問題を徹底的に調査した。
We investigated the problem completely.
部屋を徹底的に掃除した。
I cleaned the room thoroughly.
Adverb meaning 'completely' or 'entirely', often used for changes of state or when something is done fully.
Adverb meaning 'completely' or 'perfectly', emphasizing that nothing is missing or flawed.
その計画は完全に失敗した。
The plan failed completely.
To put all one's energy into an action, doing it wholeheartedly.
While 完全にやる is grammatically possible, it often sounds unnatural. Use more specific expressions like 徹底的にやる or やり遂げる depending on the nuance.
✕ 宿題を完全にやった。
I did my homework completely. (unnatural)
○ 宿題を全部やった。
I did all my homework.
すっかり忘れていた。
I completely forgot.
準備はすっかり整った。
The preparations are completely ready.
Literally 'without leaving anything remaining', meaning exhaustively or thoroughly. Formal and literary.
彼はそのテーマを余すところなく説明した。
He explained the theme completely, leaving nothing out.