How do you say why the sad face in french?

There isn't a direct equivalent of "Why the sad face?" in French. It depends on the context and what you're trying to convey. Here are some options:

To express concern:

* Pourquoi la mine triste ? (Why the sad face?) This is a direct translation, but sounds a bit formal and can be interpreted as questioning their sadness.

* Qu'est-ce qui ne va pas ? (What's wrong?) This is a more natural and gentler way to inquire about their well-being.

* Tu as l'air triste. Tout va bien ? (You look sad. Is everything alright?) This is a caring way to ask if something is wrong.

To tease playfully:

* T'es pas content(e) ? (You're not happy?) This is casual and playful, implying you're noticing their unhappy expression.

* Pourquoi la tronche de déterré ? (Why the long face?) This is a humorous and informal way to ask, comparing their expression to someone who has been digging in the dirt.

To express sympathy:

* Tu sembles triste. Je suis désolé(e). (You seem sad. I'm sorry.) This expresses your understanding and offers sympathy.

The best translation will depend on the specific situation and your relationship with the person.