How to Say "untruthful" in Spanish
The Spanish word for “untruthful” is “mentiroso” — A2 level. This is a very common word in everyday Spanish.
English → SpanishA2
adjectiveA2
describing a statement or account

Examples
Su excusa era tan mentirosa que nadie le creyó.
His excuse was so untruthful that nobody believed him.
El informe parecía mentiroso y lleno de errores.
The report seemed misleading and full of errors.
Matching Gender
As an adjective, 'mentiroso' must change its ending to match the person or thing it describes. Use 'mentiroso' for masculine things and 'mentirosa' for feminine things.
Forgetting the Gender Change
Mistake: “Ella es mentiroso.”
Correction: Ella es mentirosa. (You must match the 'a' ending to the female subject 'Ella'.)
Related Translations
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