Learn Spanish (Latin America): El doctor entra al edificio nuevo.

al is a mandatory contraction. Whenever the preposition a (to/into) is followed right away by the masculine article el (the), they combine to form al. You will never see a el written separately in Spanish!

Why do we need the a part of al at all? In English, we just say 'enters the building', not 'enters to the building'.

In Spanish, the verb entrar (to enter) needs to be followed by a preposition, usually a (or sometimes en), before mentioning the place you are going into. So literally, this sentence translates to 'The doctor enters to the new building.'

Why is the word order edificio nuevo instead of nuevo edificio?

In Spanish, descriptive words (adjectives) like nuevo (new) usually come after the thing they are describing. So, instead of 'new building', you say edificio nuevo (building new).

What if the doctor was entering a feminine place, like a clinic (clínica)? How would the sentence change?