Spanish Expression · Native
por si las moscas
just in case (idiom)
Pronunciation: por see las MOS-kas
Meaning
An informal expression meaning 'just in case' or 'to be on the safe side', implying preparation for an unforeseen event.
Example
Llevaré un paraguas, por si las moscas llueve.
I'll take an umbrella, just in case it rains.
Common mistakes & tips
- Practice por si las moscas out loud — read the pronunciation guide above and repeat.
- Use it in your own sentence today; reuse beats rereading.
- Pay attention to context: this is a native-level Spanish expression.