Who's is -A the mistery guy in pretty littel liars?

i love this show so mutch and I can't wait any more to know how's -A the anonymously person , please can you tell me who if you watch it first of caurse .

okay , its complicated. first u should kno that alison has a twin sister and her twin tricked there parents that she was alison so the real alison had to go to a mental place. so alisons twin pretended to be alison all these years and she was murdered by the real alison . SO a is the real alison and the one who died was her twin sister. get it ? ahahaha xD

Well I think we all know now that it's Mona. Honestly a shocker. Wooh.