Sagittarius is the ninth sign of the Zodiac and represents the concept of freedom. Sagittarian's are born to roam let's say, born to be free. The quest in a way, the psychic quest of a Sagittarian is to break out of the bonds, whatever bonds they feel they're in, and experience a wider world. The sign itself rules concepts such as travel, of luck, of gaining knowledge, of experiencing the world, many people, geography, etc., loves just getting out.
In relationships, a Sagittarian can't be pinned down. A Sagittarian is very sensitive and giving, loyal, doesn't lie. Certainly you get the truth from a Sagittarian. But, a Sagittarian does not want to feel pinned down as if it has to answer to certain rules, has to be on time, has to show up because you want him or her there. A Sagittarian is a great, in many ways, a great friend because it likes to explore and experience and is willing to say yes to almost anything. I would recommend a Sagittarian as a lover, a friend, someone who can add joy and sparkle to your life, but you don't necessarily have, what would I call, you don't necessarily find the Sagittarian at home when you want him or her to be there.