what is <你有事嗎?/很有事!> (Nǐ yǒushì ma?/Hěn yǒu shì!)
<你有事嗎?> (Nǐ yǒushì ma?/Hěn yǒu shì)
<What’s wrong with you?>
<Ca va bien la tête?>

English---------explication en français en bas--------
When people say «你有事嗎? » to you, make sure you don’t get it wrong, because it has two meanings. I hope that if your friend says it to you, it’s the first meaning!
<1> Literally, «你有事嗎? » means “Do you have things (to do)?” It often means “Are you available?”
For example:
1. A: 你有事嗎?我可以問你一個問題嗎?
[A: Nǐ yǒushì ma? Wǒ kěyǐ wèn nǐ yīgè wèntí ma?]
( Are you available now? May I ask you a question?)
The answer could be…
B1: 我沒事,請說。 [Wǒ méishì, qǐng shuō.]
(I’m free, please ask your question.)
B2: 我現在很多事,請你晚一點問我。
[Wǒ xiànzài hěnduō shì, qǐng nǐ wǎn yīdiǎn wèn wǒ.]
( I’m busy now, please ask me later.)
Ex: 你有事嗎?我們一起去喝咖啡。
[Nǐ yǒushì ma? Wǒmen yīqǐ qù hē kāfēi.]
(Are you available now? Let's go have coffee.)