
Questions & Answers about yoyakubangou o sukuriinshottoshite oita node, genchi de mo sugu kakunin dekimashita.
〜ておく means to do something in advance or to do something and leave it ready for later.
So スクリーンショットしておいた means the speaker took a screenshot beforehand, as preparation.
That nuance matters. It is not just I took a screenshot. It is more like:
- I took a screenshot ahead of time
- I made sure to have a screenshot ready
The past form of 〜ておく is 〜ておいた.
These two forms are easy to confuse:
- 〜ていた = was doing / had done / was in a state
- 〜ておいた = did in advance, for future convenience
So:
- スクリーンショットしていた would sound more like was taking / had taken a screenshot
- スクリーンショットしておいた clearly adds the idea of preparation
In this sentence, the speaker is saying the screenshot was taken before arriving, so 〜ておいた is the natural choice.