Questions & Answers about Не хмурься: это была всего лишь маленькая ошибка.
Basically, yes. Не хмурься means don’t frown, don’t look so gloomy, or don’t be upset.
The verb хмуриться is about looking dark, gloomy, or displeased, especially in your face. So in context, it is often a comforting line rather than a strict command. It can sound like:
- Don’t frown
- Don’t look so upset
- Don’t be glum
So the sentence has a reassuring tone.
Because the base verb is хмуриться, not хмурить.
The -ся ending often makes a verb reflexive or intransitive. Here it gives the meaning to frown / to look gloomy oneself.
Compare:
- хмурить брови = to knit/furrow one’s brows
- хмуриться = to frown / to look gloomy
So не хмурься is the natural way to say don’t frown when speaking to one person informally.