des épinards

Question

In the sentence "Tu veux des épinards", Why is it "des épinards"? I understand that des is used to mean some when things are countable. But I don't understand why spinach is considered to be countable,

Accepted Answer

Hi Janet,
I am not sure what else you would want to use instead of 'des' but it has to be plural as you can't buy one spinach.
Tu veux des épinards? = Do you want some spinach?
You cannot say in French,  
tu veux de l'épinard?
You might say,
Tu veux de la salade/ du chou?
because salad and cabbage can be bought in units in the shops. 
Hard to explain but I hope this helps!