Learn Italian: Vai da Maria? - Are you going to Maria's?

It often does! But as this lesson shows, when you use da followed by a person (like a name or a profession), it indicates movement to that person's house or workplace. So da Maria means 'to Maria's place'.

Where is the Italian word for 'house' or 'place' in this sentence?

It is built right into the preposition da when it is used with a person. You don't need to say alla casa di Maria (to the house of Maria); simply saying da Maria perfectly expresses going to her place.

Why isn't it Tu vai da Maria?

In Italian, you usually drop subject pronouns like tu (you) because the verb form already tells us who is doing the action. The verb vai can only mean 'you go' or 'are you going'.

Why is it just da Maria and not combined with an article like dalla Maria?

In standard Italian, we do not put words for 'the' (il or la) before people's first names. Because there is no article before Maria, the preposition da stands alone and doesn't combine into a word like dalla.