How do you say dont understand a word im saying in french?

Here are a few ways to say "I don't understand a word you're saying" in French, ranging from formal to informal:

Formal:

* Je ne comprends pas un mot de ce que vous dites. (I don't understand a word of what you're saying.)

* Je ne comprends absolument rien. (I don't understand anything at all.)

Informal:

* Je ne comprends rien. (I don't understand anything.)

* J'ai rien compris. (I didn't understand anything.)

* C'est du chinois pour moi. (It's Chinese to me.) This is a very informal way of saying you don't understand.

You can also use a phrase to ask for clarification:

* Pouvez-vous répéter, s'il vous plaît? (Can you repeat, please?)

* Pouvez-vous me l'expliquer autrement? (Can you explain it differently?)

Choose the phrase that best fits the situation and your level of formality.