Crédulo vs. ingenuo

There are two Spanish words, 'crédulo' and 'ingenuo', which translate to 'gullible' or 'credulous' in English. Although they appear similar, each carries a distinct nuance and usage.

Crédulo

'Crédulo' refers to someone who is easily convinced or believes things with little evidence. It usually emphasizes the readiness to believe.
Juan es muy crédulo y siempre cae en las bromas de sus amigos.
(Juan is very gullible and always falls for his friends' jokes.)
No seas tan crédulo de creer todo lo que lees en Internet.
(Don't be so gullible as to believe everything you read on the Internet.)
Los crédulos suelen ser las principales víctimas de los estafadores.
(Gullible people are often the main targets of con artists.)

Ingenuo

'Ingenuo' describes someone who is naïve or lacks sophistication, often due to innocence or inexperience. This word highlights a lack of worldly experience.
María es tan ingenua que confía en todos sin cuestionarse nada.
(María is so naïve that she trusts everyone without questioning anything.)
Su actitud ingenua le hizo pensar que todos tenían buenas intenciones.
(His naïve attitude made him think that everyone had good intentions.)
El niño era demasiado ingenuo para entender los riesgos.
(The child was too naïve to understand the risks.)

Summary

In summary, while both 'crédulo' and 'ingenuo' relate to believing things easily, 'crédulo' emphasizes a tendency to believe without much evidence, and 'ingenuo' stresses a lack of worldly experience or sophistication.