Ask someone politely not to do something (ないでください)
Take the casual negative ない-form of a verb and add でください to ask someone politely not to do something.
JLPTN5
[verb negative stem] + ないでください[verb-nai] + de kudasai
Polite negative request: please do not...
While 〜てください (te kudasai) asks someone to do something, 〜ないでください (naide kudasai) asks them NOT to do it. It is formed by taking the verb's casual negative ない-form (nai-form) and adding でください (de kudasai):
- 写真を 撮らないでください (Please do not take photos)
- ここに 入らないでください (Please do not enter here)
- 心配しないでください (Please do not worry)
- 忘れないでください (Please do not forget)
It is respectful, considerate, and standard on notices, signs, and instructions.