The prefix quot; former quot; written at the beginning of a word means quot; outside or beyond quot; and it gives to understand that it is not what it was before. In this case ex-wife to say that he is no longer the wife who was previously. When the word is simple, the prefix ex is attached to it. Example: former player, exmaestro, examigo. When the word is made up, the prefix is separated. Example: former Prime Minister, former great friend, former soldier satin, etc.