por si acaso
/poɾ si aˈkaso/
In Spanish, 'just in case' is translated as por si acaso. Wiktionary also lists por si las moscas.
Meaning: to be on the safe side (adv)
Ways to say it
| Spanish | IPA |
|---|---|
| por si acaso | /poɾ si aˈkaso/ |
| por si las moscas | /poɾ si las ˈmoskas/ |
The phrase is used as an adverb to mean being on the safe side. You can also use the shorter form por si when it is followed by a specific clause, such as por si llueve (in case it rains).
What does it mean word for word?
The phrase por si acaso literally translates to 'for if by chance', while the idiom por si las moscas literally translates to 'for if the flies [happen]'.
Which one should you use?
Por si acaso is the standard way to say 'just in case'. In contrast, por si las moscas is a more colloquial and idiomatic expression.
Related words
How does it change in a sentence?
You can use the shortened form por si to mean 'in case' when it is followed by a clause.
How do you pronounce it?
/poɾ si aˈkaso/
Did you know?
- In some regions, people shorten por si las moscas even further by simply saying por las moscas in very fast, informal speech.
- Unlike English, where 'just in case' usually comes at the end of a sentence, por si acaso can frequently be placed at the very beginning to set the tone of caution.
- Spanish speakers may use por si acaso as a standalone sentence to justify a redundant action, such as carrying two phones.
Examples in context
- Se lo aclararé, por si acaso.I will make it clear for him, just in case.This sentence shows how to use por si acaso to clarify information for someone.Tatoeba #5718356 by arh, translation #7917637 by fpp
- Coge algo de dinero por si acaso.Take some money just in case you need it.This sentence uses por si acaso to suggest taking money as a precaution.Tatoeba #2274958 by Shishir, translation #2255667 by _undertoad
- ¿Por qué no llevas un paraguas por si acaso?Why don't you bring an umbrella, just in case?This sentence uses por si acaso to suggest bringing an umbrella as a precaution.Tatoeba #9446112 by ignacio, translation #9446125 by DJ_Saidez
- Siempre llevo una chaqueta por si acaso hace frío.I always carry a jacket just in case it gets cold.
- En el caso de que perdamos el tren, tomaremos un taxi.In case we miss the train, we'll take a taxi.
- Llevo siempre mi paraguas por si las moscas.I always carry my umbrella just in case.
- Déjame anotar tu número, por si las dudas.Let me write down your number just in case.
- Toma un poco de dinero extra por si acaso.Take some extra money just in case.
- Ponte el abrigo, por si refresca.Put on your coat just in case it gets cooler.
- 8 more sentences on Tatoeba
Example conversation
Lucía and Daniel are preparing to leave the house for a walk.
- LucíaLleva una chaqueta, por si acaso.Take a jacket, just in case.
- DanielEstá bien, la guardaré en la mochila.Okay, I will put it in the backpack.
- Lucía¿Llevas las llaves de casa, por si acaso?Are you carrying the house keys, just in case?
- DanielSí, las tengo conmigo.Yes, I have them with me.
Sources
- Wiktionary, “just in case” translations and entries por si acaso, por si las moscas, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
