The english sentence could also be "wir haben Brillen"
What is the plural of Die Tasse? Why can that not be used? Or is this the word you have to use when speaking about more than one glass?
Kind of confusing, it could also be, 'Haben wir Brille?'
It'd have to be either "Haben wir Brillen?" or "Haben wir eine Brille?". You can't leave out the article in singular.
is "brille" half a pair of glasses?
It's one pair of glasses.
Are Gläser drinking glasses? The first time i saw the word i thought it meant glass like in a window (which should be singular), now I'm confused. Can the word be used both ways like in English and we have to rely on context?
Can be both depending on context.