Japanese by Example
Learning through examples in manga

Preparing by memorizing with 〜ておく

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Rize tells Cocoa to prepare by memorizing the menu. This is because Cocoa will need to know this information later, when working as a barista.

リゼ:
「メニュー(おぼ)えとけよ」

In this dialogue, ておく has been contracted to てく. The final syllable く has been replaced with け, making it a command. The final result is とけ.