〜ておく

〜ておく means to do something in advance or as preparation, or to leave something in a certain state intentionally. It conveys the idea that an action is done with future benefit in mind. In casual speech, it often contracts to 〜とく.

This is an intermediate pattern used regularly in everyday Japanese conversation and writing.

When to Use#

• Preparing in advance: ホテルを予約しておく (book a hotel in advance)
• Leaving something as-is intentionally: 窓を開けておく (leave the window open)
• Doing something for future convenience: メモしておく (make a note of it — for later reference)

When NOT to Use#

• When the action has no preparatory or intentional nuance — use the plain て-form or dictionary form
• When describing an unintentional state — use ている instead

Example Sentences#

• ワインを冷やしておきます。 — I'll chill the wine in advance.
• 同僚に連絡しておきました。 — I contacted my colleagues in advance.
• 大家さんに連絡しておきます。 — I'll contact the landlord in advance.

Practice#

Try reading these sentences aloud, then check the translation and vocabulary:

Common Mistakes#

1. Confusing with ている — ておく emphasizes deliberate preparation (someone chose to do it), while ている describes a state or ongoing action. 冷蔵庫に入れておく (put it in the fridge — for later) vs. 冷蔵庫に入れている (it's in the fridge — describing state).
2. Not using the casual contraction — In spoken Japanese, ておく → とく is very common: 買っとく, 調べとく, やっとく. Using the full form in casual conversation sounds stiff.

Related Patterns#

• 〜ている (ongoing action / state) — Next step