Breakdown of Eles começam a decorar a sala antes que os convidados cheguem.
eles
they (m)
a sala
the living room
a
to / at (direction)
começar
to begin
Questions & Answers about Eles começam a decorar a sala antes que os convidados cheguem.
Why do we use the subjunctive form cheguem after antes que?
The phrase antes que is a temporal conjunction meaning "before." In Portuguese, it always triggers the subjunctive because it describes an action (the guests arriving) that has not yet happened at the time of the main verb, making it an anticipated event.
Why is there an extra "u" in cheguem compared to the infinitive chegar?
Could I use antes de instead of antes que in this sentence?
Yes, but you would need to change the grammar. Antes de is followed by an infinitive, not the subjunctive. Because the subject changes (from "they" to "the guests"), you would use the personal infinitive: antes de os convidados chegarem. Both are correct, but antes que with the subjunctive is very common when introducing a new subject.
Why is there an a between começam and decorar?