"They will have gone to the movies when you arrive."
Translation:Elas terão ido ao cinema quando você chegar.
Not at all. I see your are clever and willing so much to learn. Just a tip: it woud be good for you to get additional information, maybe through a portuguese book. Duolingo is good at helping us to build sentences, learn new words, and so on. But there is not much information. I think that would help you. But dont mind asking any doubt. I'll be glad to answer... if i am able to :)