How do you know if the relationship will last?

They way you know is by how well you commicate. If the person tells you his day to day activities and you'll know if you have the same values. For example the other person may value spending time with his or her immediate family or the person may value building his or her own family. He or she may value commitment, harmony and respect. Most importantly the person is open with you he talks about his or her past and includes you in every area of his or her life.