Sou um artista? Posso pintar uma parede!
Sim, você é um bom artista!
why does apartmento now mean "house" please
It shouldn't. It could mean "home" but not "house." Apartamento only means "apartment".
Also, in the UK it could be translated as 'flat' but not sure if Duolingo accepts that!
'They will try and paint the apartment' should be accepted, it's common English idiom.
How come it doesn't need 'a' between tentar and pintar like some other sentences do?
Tentar requires no preposition.