Hi Aiboud The best option out of those that you listed is : Quel âge as-tu? However it is important to note that the French are very particular with how they address one another. Therefore, when in doubt as to use the formal you or the informal one, it is advised to opt for the more formal option. Thus the best answer to your question on how to ask someone's age in french would actually be : Quel age âvez-vous? I hope that helps!

quel age as tu?