I'd like to point out this piece was the second part of a three piece coursework on marriage and the 80% mark was the mark of the entire coursework and not this individual piece.
Catholics do not all take the same approach to marriage and marital problems and breakdowns. Some may look towards the main beliefs of marriage to help them whereas others may simply try to solve the problems by themselves.
Couples must realise the importance of the main beliefs and show that they understand them. There are many things the couple may do in the weeks leading up to a marriage to influence the way the couple approach marriage. For example the couple may choose to go to marriage preparation courses to learn about the different responsibilities of married life. They may also plan their wedding day very carefully to respect the fact that marriage is exclusive. They may start going to church (if they don't already) to pray that the wedding goes well and that their marriage lasts forever.
The marriage preparation courses will also help the couple decide whether they really do want to marry each other and that they are not just rushing into things. They have to realise it is a life long commitment and they must stick together through all the bad times as well as the good times. This commitment is shown in the vows. The couple must show be aware that there may be temptations during the marriage but be strong enough to overcome them and remain faithful. They must not be selfish and must respect their partners opinions as well as their own.
The couple must take the main beliefs into account if their marriage is going through a difficult time. They have to remember that marriage is a sacrament,