Grammar
N4 verb-grammar

Do in advance 〜ておく

Meaning

To do something in ADVANCE, in preparation for later, or to leave something in a certain state for the future. "Do ~ (so it's ready / taken care of)".

Formation

Notes

Two senses: (1) preparation — 宿題をやっておく ("do the homework in advance"); (2) leaving a state as-is — 窓を開けておく ("leave the window open [for now]"). Casual contracted: 〜とく (やってとく).

Examples

I'll prepare the materials for tomorrow's meeting in advance.

Breakdown
tomorrow (modifier) meeting (modifier) materials (object) prepare in advance

Please leave the light on.

Breakdown
light (object) leave on please

I bought dinner in advance.

Breakdown
dinner (object) bought in advance

Let's leave the window open.

Breakdown
window (object) let's leave open

Please write down the password (and keep it).

Breakdown
password (object) note (te) in advance please