Non capisco! Aiute.
I am unsure about when it is necessary to use the definite article. Sometimes the sentences use it as in 'tu bevi l'acqua' and sometimes it is left out. Can somebody please explain the rule?
Tu bevi l'acqua = you drink the water
Tu bevi acqua = you drink water
I think that you should err on the side of using the definite article, rather than leaving it off.
Most of the time when it is missing, on Duo, it has to do with groups of nouns or "uncountable" nouns, like water, wine, beer, rice, etc.
You can count bottles: one bottle, two bottles; but you can't count water: one water, two waters. So you'd never leave an article off of bottiglia, for instance.