Pictures instead of words
An idiom (expression idiomatique) means something other than the sum of its words. Nobody leaves a rabbit anywhere in poser un lapin. Most idioms belong to conversation: they make a statement livelier without changing what it says.
Same statement, two colours
Neutral
Leur nouvel appartement a coûté très cher.
Their new flat was very expensive.
Il n'est pas venu au rendez-vous.
He didn't turn up for our date.
Je suis un peu triste depuis dimanche.
I've been a bit sad since Sunday.
Idiomatic
Leur nouvel appartement a coûté les yeux de la tête.
Their new flat cost an arm and a leg.
Il m'a posé un lapin.
He stood me up.
J'ai le cafard depuis dimanche.
I've been feeling down since Sunday.
Different language, different picture
English often has an idiom with the same meaning but a different picture. That is exactly where word-for-word translations appear that nobody understands.
Same meaning, different picture
| French | Literally | English |
|---|---|---|
| avoir un chat dans la gorge | to have a cat in your throat | to have a frog in your throat |
| tomber dans les pommes | to fall into the apples | to pass out |
| mettre les pieds dans le plat | to put your feet in the dish | to put your foot in it |
| donner sa langue au chat | to give your tongue to the cat | to give up guessing |
| il pleut des cordes | it's raining ropes | it's raining cats and dogs |
| avoir d'autres chats à fouetter | to have other cats to whip | to have bigger fish to fry |
Il faisait tellement chaud qu'une passagère est tombée dans les pommes.
It was so hot that a passenger passed out.
Il a mis les pieds dans le plat en parlant du divorce de Claire.
He put his foot in it by bringing up Claire's divorce.
Je donne ma langue au chat, c'est quoi la réponse ?
I give up, what's the answer?
Moods and states
A great many idioms describe how someone is feeling. They are very common in everyday speech and sound neither sloppy nor forced.
Je ne suis pas dans mon assiette aujourd'hui.
I'm feeling a bit off today.
Elle a la pêche ce matin !
She's full of beans this morning!
Depuis la naissance de leur fille, ils sont aux anges.
Since their daughter was born, they've been on cloud nine.
J'en ai ras le bol de ces réunions inutiles.
I'm fed up with these pointless meetings.
What is fixed and what moves
The core of an idiom is fixed: you don't swap its article, noun or preposition. The verb, however, is conjugated as usual, and a possessive follows the subject.
Ce week-end nous a coûté les yeux de la tête.
That weekend cost us an arm and a leg.
Verb in the passé composé, the rest stays.
Mon frère n'est pas dans son assiette.
My brother is feeling a bit off.
The possessive follows the subject: mon, ton, son …
Ce n'est pas la mer à boire.
It's not rocket science.
This idiom is almost always negative.
When an idiom fits
Most idioms are courant or familier. In conversation, messages and casual emails they sound natural. In a report or an official letter, stay neutral. And use them sparingly: one well-placed idiom sounds confident, three in a row sound memorised.
Two situations, two choices
Report
Le projet a largement dépassé le budget prévu.
The project went well over the planned budget.
Conversation
Ce projet nous a coûté les yeux de la tête.
That project cost us an arm and a leg.
