ておくPrepare in advance; leave as is
ておく describes intentionally doing something now because it will be useful later. It can also mean deliberately leaving something in its present state for the time being.
Preparation for later
The most common use presents an action as preparation for a foreseeable event or need. The later purpose may be stated directly or may already be obvious from the situation.
会議の前に、参加者の人数を確認しておきます。
I’ll check the number of participants before the meeting.
AnalyzeLeaving something in a useful state
ておく does not always translate as “in advance.” It can describe a deliberate decision to preserve a condition because that condition will be useful.
ペンキが乾くまで、窓は開けておいてください。
Please leave the window open until the paint dries.
AnalyzeAction versus prepared state
ておく draws attention to the intentional action of preparing something. てある instead draws attention to the resulting state that has been deliberately arranged.
The final verb carries the ending
Tense, politeness, and negation are shown by changing the final おく. A negative or past-negative form often says that necessary preparation was not done.
予備の鍵を作っておかなかったので、家に入れませんでした。
I hadn’t made a spare key, so I couldn’t get into the house.
AnalyzeMore examples
出発前に切符を買っておく。
I’ll buy the ticket before leaving.
Analyzeお客様が来る前に、お茶を冷やしておきました。
I chilled the tea before the guests arrived.
Analyze質問を忘れないように、ノートに書いておきます。
I’ll write the question in my notebook so I don’t forget it.
Analyze明日は店が休みなので、今日のうちに食料を買っておきましょう。
The store is closed tomorrow, so let’s buy food today.
Analyzeこの箱はあとで使うので、ここに置いておいてください。
We’ll use this box later, so please leave it here.
Analyzeこのドアは荷物を運び終わるまで、開けておきます。
I’ll leave this door open until we finish carrying the luggage.
Analyze旅行の前に、ホテルを予約しておきませんか。
Shall we book the hotel before the trip?
Analyze