Few people are born being able to communicate as a couple, so this is considered a learned behaviour. Many children grow up watching their parents communicate, and it helps them shape their own ability as they mature. Modern marriages often end in divorce, and many children do not learn good communication skills from their parents. They instead learn how to communicate in an antagonistic manner, and this will not assist them when they begin their own relationship. They may need to seek professional help if they do not find good examples elsewhere in their life.
When a person knows what they want, they have to be able to express it to a partner. This is a communication skill that has long been highlighted, and it is a necessity for those who want to successfully communicate. Learning to verbally express wants and needs is important, and doing it in a clear and concise manner is best for a good relationship. Emotionally blurting out information is generally not a good communication method with a partner, and it will often fail to get across important information.
Listening is often the most important communication skill people can learn, and it enhances a relationship more than the ability to express wants and needs. If a person's partner fails to listen to them, they are unlikely to be successful when communicating. Likewise, the person who has communicated must also be willing to listen to their partner's answer or rebuttal. Give and take in communication is what makes it successful.
There is no completely right or wrong way to communicate with a partner, and that is why it is more of an art than a science. Couples who have been together for decades may not have much need for verbal communication. They have learned each other's body language and expressions, and this helps them understand what their partner wants or needs without ever saying a word.