German phrase
In welche Klasse gehst du?
Meaning
What grade are you in?
When to use it
It asks your school grade. Use it when meeting a new friend.
Example dialogue
Ich bin neu an der Schule. In welche Klasse gehst du?
I'm new at this school. What grade are you in?
Ich gehe in die vierte Klasse. Ich heiße Emma.
I'm in fourth grade. My name is Emma.