When referring to a person who has completed something, whether it be a job, political office, or marriage/relationship should you use the term “ex-” or “former”?
This is a pet peeve of mine, as I often hear people use “ex” when they should use “former”. Usually, “ex-”, which is a prefix, is used if the person left the position in question under less than stellar conditions. For example, if a politician has been forced to leave office before the end of his or her term because of some shady or illegal dealings, it would be correct to call that person the “ex-mayor” or “ex-congressman”, etc. Usually, the end of a marriage or relationship is not on such good terms, which is why the person is called your “ex-”.
However, if the person’s tenure is just over, then the proper term should be “former”. “Former” just says that the term or condition is over, period. The situation ended because it was supposed to, not because of any negative circumstances.
What is the different between ex and former?
Ex is more final. If you said, "that person is former colleague," it's neutral but "ex-colleague" suggests that you repudiated
them in some way. Maybe a better example, you could say "in my former life" (either in reference to your previous
incarnation or just a different living situation you were in before) but you couldn't say "my ex-life", it doesn't make sense
because you are alive.
Also ex is more restricted grammatically, because it is truly a prefix. You can say "my ex-apartment is near here" or my
former apartment is near here", or you could say formerly, "I lived near here"; but you can't say "Exly, I lived near here", or "I
exly lived here." You'd have to say, "I once lived here".
However, ex also has the meaning of a noun when you speak of your "ex" to mean your ex-spouse or ex-partner. You can't
say "my former" and have people any idea what you mean. But "my ex" has a whole lot of meaning.