When the conjunction particle て
is followed by the う-Verb
置（お）く in Japanese, it regularly has the meaning of ‘to do (A) in advance’. 置（お）く as a verb itself means ‘to place something’ (down), but also has the nuance ‘to leave something alone’, or to ‘drop something’ (like a topic). In this way, ておく
can be thought of as meaning ‘to do (A) and leave it (until later)’.
Before sleeping, I will wash the dishes in advance. (So that it does not need to be done later)
I am going to put your wallet in your bag. (So that you won't forget it later)
I am going to make a reservation in advance. (So that the bookings don’t fill up while we wait)
When using ておく
, the ‘future event’ that the (A) action is being done for may be something that is coming soon, or may be something that the speaker doesn’t want to ever come. Due to this, ておく
is also regularly used when the speaker is doing something specifically to prevent another thing from happening.
If you brush your teeth everyday, you will be able to prevent cavities. (That may or may not come in the future)
is sometimes contracted to とく
in verbs where て
would usually be said as で
). Although this is not excessively common in conversation, it is very common in drama, manga, and similar media.
I am going to leave the passport we need for the trip tomorrow on top of the table in advance. (So that I won’t forget it later)
I am going to fill this thermos up with water in advance. (So that it is available when I am thirsty)