So glass can mean glass where you pour some liquid and it can mean glass itself as material.
So for example when you say "does glass float or sink?", how to understand what it means? Let say I want to ask for actual glass material, not glass (of water).
What is the best way to specify it, so people would understand what I am talking about?
P.S. in my native language those are different words, so it is easy to understand.