How to Say "childish" in Spanish
The Spanish word for “childish” is “infantil” — B1 level. This is a very common word in everyday Spanish.
English → SpanishB1
adjectiveB1neutral/informal
immature behavior

Examples
No seas infantil, compórtate como un adulto.
Don't be childish; behave like an adult.
Tuvimos una discusión muy infantil sobre quién usaría el control remoto.
We had a very silly argument about who would use the remote control.
Su excusa era tan infantil que nadie la creyó.
His excuse was so childish that no one believed it.
Using 'Ser' vs. 'Estar'
When describing someone's typical personality, use 'ser' (e.g., 'Él es infantil'). If describing a temporary behavior, you might use 'estar' (e.g., 'Hoy estás muy infantil').
Related Translations
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