Yap.Town

の、忘れないでよ

don't forget to

→ の
phrase Rare #44,054
don't forget to の turns the preceding action into something to remember. 忘れないでよ is a casual, emphatic way to say “don't forget.”
JA: 薬を飲むの、忘れないでよ。
EN: Don't forget to take your medicine.

図書館に本を返すの、忘れないでよ。

Don't forget to return the book to the library.

ドアを閉めるの、忘れないでよ。

Don't forget to close the door.

窓を閉めるの、忘れないでよ。

Don't forget to close the window.

タバコの火を消すの、忘れないでよ。

Don't forget to put out your cigarette.