“Être bête comme ses pieds” is one of my all time favorite French expressions. The literal translation is “to be stupid like his (or her) feet”. The idiom has lots of English equivalents including “to be dumb as a bag of nails”, “dumb as a rock”, “dumb as a doorknob”, “thinkheaded” and “so stupid”, among others.
Être bête comme ses pieds
to be very stupid
Expression origin
This expression dates from the nineteenth century, where the feet were said to be the body part the furthest from the head or “seat of thoughts”, and thus associated with total stupidness or stupidity.
Example sentences
This first example sentence uses the advanced negation form ne…que, which means “only” or “just”.
Le président avait plusieurs mois pour répondre à la crise sanitaire et il ne fait que nier la situation. Il est bête comme ses pieds!
The president has had several months to respond to the health crisis and all he’s done is deny the situation. He’s as dumb as bag of nails.
Le maire de cette ville est bête comme ses pieds. Ça fait quatre ans qu’il a son poste et il n’a rien fait!
The mayor of this city is dumb as rocks. He’s been in his position for four years and he hasn’t done anything!
Note: There’s another common French expression which uses bête: “bête comme chou”. The literal translation here is “stupid” as cabbage” but the meaning is “easy as pie”, “dead easy” or “dead simple”.