What does it mean word for word?
The component Qu'est-ce que literally translates to "What is it that".
Which one should you use?
You can use Que dites-vous? for a more formal tone. If you specifically want someone to clarify the meaning of their words, you can use Que voulez-vous dire? For a very colloquial and common way to ask among friends, you can use Tu dis quoi ?
Is there a formal and an informal way to say it?
The phrase Qu'est-ce que tu dis ? is considered informal. For formal situations, use Que dites-vous? In a social setting, if you want to be more polite when asking someone to repeat themselves, it is more common to use Comment ? Among friends, the very informal Tu dis quoi ? is frequently used.
How does it change in a sentence?
When speaking to a stranger, a superior or a group of people, use Qu'est-ce que vous dites ? instead of Qu'est-ce que tu dis ?
Did you know?
- Among young people, the phrase Tu dis quoi ? can actually function as a greeting meaning 'What's up?' rather than a literal question about spoken words.
- In some French-speaking regions, saying Qu'est-ce que tu dis ? with a sharp tone can shift the meaning from a request for repetition to a challenge of the other person's logic.
- The word tu in this phrase is a cognate of the German word du and the Russian word ты, all descending from a Proto-Indo-European root.
Examples in context
- Vous avez dit quelque chose d'important. Que dites-vous exactement?You said something important. What are you saying exactly?
- Attends, je n'ai pas entendu distinctement. Qu'est-ce que tu dis?Wait, I didn't hear clearly. What are you saying?
- Qu'est-ce que tu dis ?What are you saying?
- Pardon, qu'est-ce que tu dis ?Sorry, what are you saying?
Sources
- Word origins: Wiktionary entries que, tu, CC BY-SA 4.0.