One of the advantages of living together before marriage is getting to know a person that you might marry with. It is important for a person to know almost everything about the other person that he/she is going to get marry with. However, it can't be accomplish without living together for a while before getting married. People need to know how a person is handling his/her life from all aspects such as behavior, mental, financial and others before a person decides to get married with. This can not be completed in a few days, therefore, it is important to live together for a while before deciding weather to get married or now.
Also, learning about a person's abilities to satisfy your expectations is something important to know before getting married. Different people have different expectations that could be satisfied by different people. They are such as some husbands expect their wives to dress in certain ways or the vice versa, or some wives expect their husbands to work while the wives want to take care of the kids. In order to learn if one is able to fulfill other's expectations, once again they need to live together before getting married.
On the other hand there are disadvantages in living together