I will Highlight below,the reason why most relationships don't work. 

1.No Love: Any relationship without love or chemistry can never have free flow of expression of care.  They two parties can't express their love because it never existed in the first place.  Which will in the long run destroy the relationship. 

2.Complain: One thing people hate subconsciously is to get nagged especially if it's done repeatedly.  A relationship that is full of complains can't last.  It's just as simple as that. 

3. Bad Attitude : Attitude is a very important aspect of a relationship.  It can make or mar a relationship and it's highly advisable to have a positive and sensible attitude towards relationship matters. 

You should watch the way do things cause it might be the determinant wether  you will stay longer with your partner or not.