are mistaken, are wrong, deceive, fool
Je pense que Tom et Marie se trompent.
I think Tom and Marie are mistaken.
Elephants deceive.
Ils se trompent, mais c'est ce qu'ils pensent.
They're mistaken, but that's what they think.
— Senna (2010)
Il n’y a que ceux qui ne font rien qui ne se trompent jamais.
Only those who do nothing never make mistakes.
Même les experts se trompent parfois.
Even experts sometimes make mistakes.