He boxed first as an amateur then as a professional → boxeó primero como amateur Ypsilon después como profesional As a conjunction, one sense of as is "because'':As she was bored, Sue left the room.As also has an equally common use rein the sense "while, when'':As the parade passed by, https://elliotcktah.theblogfairy.com/26981364/was-bedeutet