～ておく (in advance)

Japanese Grammar Basic Japanese ★★★★ 4/5 neutral おくoku
読み おく
ローマ字 oku
形 Verb て-form + おく/おきます

意味

An auxiliary verb attached to the て form indicating that an action is done in advance, in preparation for a future need or situation. It conveys the idea of doing something ahead of time and leaving the result in place.

ておく emphasizes forethought and preparation — the speaker consciously does something now so that it will be useful or convenient later. For example, buying groceries before guests arrive or studying before an exam. It can also express leaving a state as it is, either deliberately or by neglect, such as leaving a window open or letting food cool. In casual speech, ておく contracts to とく (e.g. 買っておく→買っとく), which is extremely common. The polite form is ておきます. Learners sometimes confuse ておく with てある; the key difference is that ておく focuses on the act of preparation, while てある focuses on the resulting state.

例文

  1. 明日のために弁当を作っておいた。
  2. 旅行の前にホテルを予約しておきます。
  3. 会議の資料をコピーしておいてください。

使い方ガイド

場面: spoken, written, everyday

トーン: practical

正しい言い方

  • テスト前に教科書を読んでおいたほうがいい。
  • お客さんが来る前に部屋を掃除しておこう。
  • 必要な情報を調べておきました。

避ける言い方

  • 昨日テレビを見ておいた。(Using ておく for a leisure activity with no preparatory purpose) → 昨日テレビを見た。
  • 窓が開けておく。(Using が instead of を — the object being prepared takes を) → 窓を開けておく。

起源と歴史

おく originally means 'to place' or 'to put down.' The auxiliary use extends this to mean performing an action and placing or leaving the result in readiness for the future.

文化的背景

世代: All ages

社会的背景: Universal

関連フレーズ

～て (て form) The て form is one of the most versatile verb and adjective conjugations in Japanese. It connects clauses, forms compound verbs, makes requests, and serves as the base for many auxiliary constructions such as ている, てしまう, and ておく. ～てくる (1) (directional) An auxiliary verb construction where くる follows the て form to express that someone or something moves toward the speaker. It indicates physical movement in the direction of the speaker's location. ～てみる (try doing) An auxiliary verb construction where みる follows the て form to express trying or attempting an action to see what happens or what it is like. It conveys the nuance of doing something experimentally or for the first time. ～ことができる (able to) A construction expressing ability or possibility. It states that doing a particular action is possible, either because of personal skill, circumstances, or permission. It is the formal equivalent of the potential form of verbs. ～すぎる (too much) An auxiliary verb attached to verb stems and adjective stems to express that something is done excessively or a state is excessive. It conveys the meaning of 'too much' or 'overly.' ～ていく (1) (moving away) An auxiliary verb construction where いく follows the て form of a verb to indicate that an action or movement proceeds in a direction away from the speaker or a reference point. It describes going somewhere while doing something, or doing something and then going. ～ていく (2) (ongoing change) An auxiliary verb construction where いく follows the て form of a verb to express that an action or state continues to change or progress from the present into the future. It describes a gradual, ongoing shift moving forward in time. ～てくる (2) (emerging change) An auxiliary verb construction where くる follows the て form to express that a process or change has begun and progressed up to the present moment. It describes an emerging or continuing change observed from the speaker's current perspective.
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