Infantil vs. pueril

The Spanish words 'infantil' and 'pueril' both relate to childlike qualities, but they have nuanced differences, particularly in their connotations and usage.

Infantil

'Infantil' refers to something related to children or infancy. It is often used in a neutral context without negative connotations.
Ella tiene una naturaleza muy infantil.
(She has a very childlike nature.)
Le encantan los programas de televisión infantiles.
(She loves children's TV shows.)
La literatura infantil es esencial para el desarrollo de los niños.
(Children's literature is essential for the development of children.)

Pueril

'Pueril' usually has a negative connotation and refers to childish or immature behavior, suggesting a lack of maturity or seriousness.
Su actitud fue totalmente pueril durante la reunión.
(His behavior was totally childish during the meeting.)
Deberías dejar de comportarte de una manera tan pueril.
(You should stop behaving in such a childish manner.)
Sus bromas eran tan pueriles que nadie se rió.
(His jokes were so childish that nobody laughed.)

Summary

While 'infantil' is typically neutral and refers to things related to children, 'pueril' carries a slightly negative tone, implying that someone's actions or behavior are immature or unbecoming of their age.