Learn Portuguese (Portugal): Eles estão a pintar a parede da sala.

In European Portuguese, actions happening right now are expressed using the verb estar (to be) plus a plus the infinitive form of the main verb. Here, estão a pintar translates to 'they are painting'.

Why is the main verb pintar not conjugated to match Eles?

In this sentence structure, only the helping verb estar is conjugated to match the subject (Eles estão). The main action verb always stays in its basic dictionary form, which is the infinitive (pintar).

Why is it a parede da sala and not a sala parede for 'the living room wall'?

In Portuguese, you cannot stack nouns together like we do in English. You have to say 'the wall of the living room'. The word da is a required contraction of the preposition de (of) and the feminine definite article a (the).

Does the word sala just mean 'living room'?

Sala translates to a general 'room', but in everyday conversation it almost always refers to the living room. If you need to be very specific, you can say sala de estar for living room and sala de jantar for dining room.