Gemini is the more communicative, childish and excitable sign within the zodiac. The ruler of this sign is Mercury. Its natural house is the third house.
Intellect
Gemini's natives tend to be restless, intellectual folks. They are mental people by nature, and have a dynamic spirit that is intellectually impressionable and inspired by pure ideas. This dynamism allows them to default to a more positive mental state.
They are able to enjoy synthesizing bits of information to get a good idea of what is going on. However, this may come at the expense of deeper understanding of things or verifying their integrity all the way through.
They love having a discussion and sharing things, and it can have a great soothing effect on them when they are in a bad mood. Gemini's natives love finding common grounds with people. Not only that, but they need some attention, and can become resentful when people do not talk to them. They have natural cynical inclinations, especially when there is no constructive communication going on.
Communication and humour
On a general note, these natives tend to be friendly, but are often self-serving. They can be quite cool and calculated, however influence from Venus or Moon can help rebalance this and make them more thoughtful. These natives just love having a good laugh, but may sometimes annoy others in the process.
There is a tendency to be social butterflies, unless Saturn is strong or there are other introspective elements in the astrology chart. These natives can be somewhat childish in demeanor, sometimes a bit lacking in responsibility, unless the chart shows strong mature indications.
Likewise, they can be quite humorous and usually have a rather bubbly and stimulating personality, which can attract many admirers. Communication and interactions are fundamental in this sign, Geminis can lose themselves when these are missing or ineffective. They need to know what is going on, or they may imagine bad things.
They do need friends and a social life in order to feel complete. For this reason, they really need a partner who is just as social and can keep up with them. Gemini's natives have a reputation as an unfaithful sign. This, however, is a misconception, for when truly in love, Geminis can be loyal.
They seek stimulating experiences, and although being somewhat intellectual in nature, they can get bored and lose their interest rather quickly. Nevertheless, they have a great wit, rather curious and inquisitive by nature. They dislike thick-headed people. Gemini's natives are so mentally active that they can be forgetful.
Emotion and temper
Geminis have both an intellectual and an emotional character. They are able to see things not only with cold logic and reason, but also with emotion and intuition. This has much to do with why they seem so fickle. It is not an intentional thing, they just vacillate between these two different points of view.
This dualistic nature gives rise to ambivalence, which amongst other things, makes them able to find great forgiveness where others seem to hold on to the hurt. As such, if a friend should lie to them, or if a lover is unfaithful, they still could not find it in their hearts to really hate the person.
For them, life is too short to feel hate towards someone. But depending on what the cause of the grudge was, Geminis have a holding grudge they can carry around for years.
Geminis usually have very strong personalities. They may look like butterflies, but can sting like bees and be verbally and mentally damaging. An annoyed Gemini can be rather manipulative, and cause great damage all-around. Geminis usually have a friendly disposition, but they will do everything to protect themselves, their egos and those they care about. When they are crossed, a ferocious temper can be aroused: a terrifying sight to behold.
They need to learn to keep this under control and keep a cool, levelled mind, so they do not cause incidental damage to their own interests or alienate people they care about. Though their temper is passionate, it does not last long in such extreme levels and rather shifts to a more dynamic, ambivalent phase. Their level of independence and their ability to accomplish goals makes this one of the more durable, inflexible signs.
Compared to Sagittarius
There is a naturally stressful 180-degree angle between these signs. Unlike Sagittarius, Gemini is somewhat less goal oriented and more interested in experience. It is also more purely intellectual, perhaps a bit mechanical and does not usually deal with belief systems, which Sagittarius does like to revel in. Gemini's natives tend to be more secular and calculated, which can clash with Sagittarius' moral, faithful approach.
Compared to Taurus
These signs are adjacent to each other. Their natives have different mentalities, Geminis tends to like Taurus's clear and direct communication style. Taurus people are usually straightforward and honest, and so Gemini usually does not have reasons to question their motives.
The issue in this association is that Taurus natives can sometimes make Geminis bored. The last ones, are more mentally adventurous, where Taurus "thinks square". Geminis are more dynamic, and can change their mind about things. Taurus people can help ground Geminis and make them more practical and effective. This relationship can be good if there are common interests or shared occupations.
Compared to Cancer
These signs are adjacent to each other. They generally work on different levels, so they may not naturally match-up. Cancer, which lives more on the emotional level, may find Gemini's more detached and desensitized nature a bit disconcerting, while Gemini functions more on the mental level, so Cancer is not a very good intellectual partner for it.
Geminis may belittle the intellectually slower Cancers and their emotional, less logical thinking patterns. For this reason, Cancers may feel insecure. There are often issues of values between these signs.
Compared to Scorpio
There is a problem between these signs on the basis of communication compatibility, as Geminis like to communicate and share, and Scorpios are much more secretive and reserved. Since they are seekers of truth, Geminis may perceive this as dishonesty. This can introduce some distance between these signs.
They may see Scorpios as moody, cold, and jealous. On the other hand, Scorpios, see Geminis as inconsistent and superfluous. Usually, they have a hard time feeling they can really trust a Gemini. Geminis may feel oppressed in an intimate relationship with a Scorpio due to their inability to control their own emotions.
Therefore, they fail to satisfy each other's need for emotional intimacy. This can be quite a tense couple. In some cases, Geminis may react to the overbearing quality of such a relationship with infidelity.
Compared to Leo
There is a potential competitiveness between these signs. The more intellectual Geminis can sometimes have a problem with the simpleminded nature of Leos, and Leos may have a problem with Geminis taking away attention from them.
That considered, both signs have a childish, fun and playful touch to them, and may attract on this basis. In a more romantic context, these signs can be a good match. They are often attracted to each other and this relationship can be quite fun.