N4
ないで(依頼)
ないで(いらい)
Please don't …, casual request
母が娘に:「知らない人についていかないで!約束よ。」
Mother to her daughter: 'Please don't go with people you don't know! Promise me.'
Explanation
「〜ないで」 at the end of a sentence is the casual form of 「〜ないでください」 with 「ください」 dropped. It means 'please don't …' and sounds friendly with friends, family and younger people: 「そんなに見ないでよ」 (Don't stare at me like that), 「もう泣かないで」 (Don't cry any more).
Mixed up with
Three levels: formal and polite 「〜ないでください」; casual and close 「〜ないで(ね)」; harsh prohibition, dictionary form plus 「な」: 「行くな!」 (Don't go!).
In listening, 「〜ないで」 has a pleading tone ('please don't …'). Do not hear it as a cold ban.
Do not use it with a boss or an elder.