"What is your age?"
Translation:Wat is jouw leeftijd?
You know what? I once tried to use this exact phrase in REAL LIFE speech. I asked my Dutch friends, "wat is jouw leeftijd". They were a bit shocked and then they laughed at me. They said "we hope, our life time is at least 90 years or more". It was like I asked them, when they are going to die. When they heard this expression, they thought I was interested how many years their life will last. So, better don't use this phrase, if you don't want to pass for a wierdo. Just use "hoe oud ben je?" instead.