What makes an unhappy couple stay together?

I think it because they have their differences

There could be many reasons. Some that none of us will ever understand unless we go through it ourselves. I personally could not be with someone just because there are kids involved. Kids can still have both parents, without the parents being together.

There are many reasons. One would be that they are working on their problems and want to bring their previously happy relationship back.

i think some stay together until all the children finish schooling.

I would say some couples stay together that are unhappy in their marriage because they do not want their kids to have to live with one parent and then the other have visitation rights. Some are stuck so they stay together even if they are miserable. It is sad. Here in Israel it is hard to get a divorce even if unhappy in the marriage. I filed for divorce 2 years before I got my divorce and had to wait for my ex to give me one. He was afraid and could not afford to do it so I had to wait 2 more years to get one. There are women that cannot get out of their marriages because the men will not give them a divorce and so try and get money out of them. It is very very sad that they are stuck.

If there are children then that is a primary reason

A lot of times it's for the sake of the kids. Also in abusive relationship there is an unhealthy kind of dependence and worthlessness felt by the victim and they force themselves to stay in the relationship

There are so many reasons that may make a couple stay together, even though they aren't happy. It can be hard to understand sometimes.

not sure.If they are unhappy find out the reason why or leave

It is hard to understand unless you are in it. I was in an unhappy marriage for many years because I wasn't ready to give up. I tried hard to make it work and to keep our family together but in the end I realized that I was sacrificing my happiness. It would never be the marriage I wanted or the happiness I deserved. Once I left it was like a huge weight had been lifted from my shoulders. I left like I wasted so many years of my life but at least I know I gave it my all but one person can't make it work. I would never do that again.