She is a very determined person, and needs a substantial amount of independence. She is unlikely to start many arguments, but will be stubborn if you try to push her too far. She needs a lot of space, even when she is married. Her attitudes towards marriage are usually quite conservative. While she may not show her affection quite as openly as other signs, she will remain faithful.
Capricorn men are fairly conservative.
Don't try to make him enjoy an active social life if her prefers not to. He is likely to have a few close friends, and may just prefer to spend time with them. He will not want a huge number of acquaintances. Above all, Capricornians need space. They are independent people, and do not appreciate too much interference in their lives.