another test

Hello to all.. hope ur day is better than mine today... im so sad.. just want to ask a question... when do you know your marriage is over??? and what signs are there to tell you move on.... some marriages go through a worldwind of stuff but they last and then there are some marriages that are just there out of convenience... what happens when there is no more excuse of why you should stay when all along it was not meant to be and hou knew this for such a long time... please all answers are welcome