Dicho español · Spanish proverb
«En boca del mentiroso, lo cierto se hace dudoso.»
Word for word
In the mouth of the liar, the certain becomes doubtful.
What it really means
The closest English equivalent: A liar's truth is still doubted.
Used to say that someone who has a reputation for lying won't be believed even when telling the truth. It highlights how a bad reputation for dishonesty destroys credibility.
Hear it in a sentence
En boca del mentiroso, lo cierto se hace dudoso; ya nadie le cree aunque diga la verdad.
A liar's truth is still doubted; nobody believes him anymore even when he tells the truth.
Why learn dichos?
Proverbs like this one are everywhere in spoken Spanish — dropped mid-conversation, usually just the first half, with the rest left for you to complete. Recognizing them is one of the fastest ways to sound less like a textbook and follow real speech. Every Lingocito edition signs off with the dicho del día, so you meet one a day next to news written at your exact level.