How do you get over someone when you know it wouldn't work?

Just get over them

Try to put that person behind you, stay out of a relationship for a while and get your good close friends around you. When you feel its time get back out there and try to find a reliable guy/girl, that person will completely clear your mind of those who have hurt you.

Answer

No one can really know for sure whether a relationship will work or not unless you've been in that particular relationship for some time and you have seen that it's not working out. If you love someone that much that you are having difficulty getting over them maybe it's worth your while to see if the relationship will work, if you haven't already.