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JLPT N4Verb Forms

てしまう— Completely Done / Regrettably Did

Indicates an action was carried through to completion — often with a nuance of regret, unexpectedness, or accident, and sometimes simply total completion.

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Pro lessonUNIT 76 · VERB FORMS

Structure · 形

[Verb te-form] + しまう

Examples · 例文

  • 宿題を忘れてしまいました。

    Shukudai o wasurete shimaimashita.

    I ended up forgetting my homework. (regret)

    忘れて + しまいました = forgot (regrettably)

  • 本を全部読んでしまった。

    Hon o zenbu yonde shimatta.

    I finished reading the whole book.

    読んで + しまった = read it all the way through (completion)

  • 電車の中でさいふをなくしてしまいました。

    Densha no naka de saifu o nakushite shimaimashita.

    I ended up losing my wallet on the train. (accident/regret)

    なくして + しまいました = lost it (accident + regret)

Usage notes · 注意

  • Casual contractions: 〜てしまう → 〜ちゃう; 〜でしまう → 〜じゃう.
  • Very common: 食べちゃった (I ended up eating it), 忘れちゃった (I forgot it).
  • The contraction sounds more natural in casual spoken Japanese.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones てしまう is tested against.

vsておく

てしまう = an action completed, often unintended/regretted; ておく = an action done deliberately in advance for future benefit.

vsてみる

てみる = try an action to see the result; てしまう = the action ends up fully done (frequently by accident).

More verb forms

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