vs 

QUICK ANSWER
"Mentiras" is a form of "mentira", a noun which is often translated as "lie". "Tonterías" is a form of "tontería", a noun which is often translated as "nonsense". Learn more about the difference between "mentiras" and "tonterías" below.
la mentira(
mehn
-
tee
-
rah
)
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
feminine noun
a. lie
Descubrí que todo era mentira.I found out everything was a lie.
2.
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
(colloquial)
(anatomy)
a. white spot
Las mentiras de las uñas no se deben, como solía creerse, a una falta de calcio.White spots on fingernails are not caused, as was commonly believed, by a lack of calcium.
Copyright © 2025 Dictionary Media Group, Inc.
la tontería(
tohn
-
teh
-
ree
-
ah
)
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
feminine noun
a. nonsense
¡Qué tontería! Yo nunca diría algo semejante.That's nonsense! I would never say something like that.
b. stupid thing
Decir eso es simplemente una tontería.That's just such a stupid thing to say.
a. foolishness
Un día tus tonterías te van a meter en problemas, hijo.Your foolishness will get you into trouble one day, son.
b. silliness
Las tonterías y las bromas de mi esposo siempre me hacen reír.My husband's silliness and stupid jokes always make me laugh.
a. silly thing
Mis amigas y yo consideramos que se separaron por tonterías.My friends and I think that they broke up over such silly things.
b. trifle
Por una tontería, hace 40 años que mis tíos no se hablan.My uncles haven't spoken to each other in 40 years over a trifle.
Copyright © 2025 Dictionary Media Group, Inc.