Vetro vs. bicchiere
While English uses the single word "glass" to describe both a raw material and a drinking vessel, Italian distinguishes between these two concepts using separate words. Use vetro when speaking about the substance itself, and use bicchiere when referring to the container you drink from.
Vetro
A2This word refers strictly to the material. You use vetro when talking about windows, broken shards, the substance used to make objects, or artistic glasswork.
La finestra è fatta di vetro resistente.
(The window is made of strong glass.)
Attenzione, c'è del vetro rotto sul pavimento.
(Careful, there is broken glass on the floor.)
Dobbiamo buttare questa bottiglia nel contenitore del vetro.
(We must throw this bottle in the glass recycling bin.)
A Murano gli artigiani lavorano il vetro in modo incredibile.
(In Murano, artisans work glass in an incredible way.)
Ho pulito il vetro della macchina questa mattina.
(I cleaned the car glass this morning.)
Bicchiere
A1This word refers to the object used for liquids. You use bicchiere when asking for a drink, describing the cup itself, or measuring a quantity of liquid.
Posso avere un bicchiere d'acqua, per favore?
(May I have a glass of water, please?)
Il bicchiere è caduto dal tavolo.
(The glass fell off the table.)
Luigi ha alzato il bicchiere per fare un brindisi.
(Luigi raised his glass to make a toast.)
Metti i bicchieri puliti nella credenza.
(Put the clean glasses in the cupboard.)
Basta aggiungere un bicchiere di latte alla ricetta.
(Just add a glass of milk to the recipe.)
Summary
To choose the correct word, ask yourself if you are talking about the material or the object. If you are discussing the transparent substance found in windows or mirrors, use vetro. If you are discussing the cup you hold in your hand to drink wine or water, use bicchiere.