Mercury in Gemini:
Mercury in Gemini people are generally quick-witted. They can come across as somewhat scattered, and this is mainly due to their eclectic interests. They seem to know a little about everything.
Turn to Mercury in Gemini men and women for lots of facts and figures as well as broad knowledge. Their learning is a little superficial — they generally have too many interests to delve too deeply into any one.
These natives learn best in a stimulating environment. They get bored easily, but they are fast learners. Impressionable to a fault, Mercury in Gemini people pick up more from their environment than most, and they can process information at lightning speed! The restlessness of Gemini is especially obvious when Mercury is placed in the sign. There is a nervous energy here that is unmistakable.
Although Gemini is a rather open-minded sign, there is often a bias towards logic. Unless Mercury forms an aspect with the Moon in the birth chart, Mercury in Gemini natives don’t always rely on intuition, nor do they take into account the world of emotion in their decision-making processes. In this sense, they can come across as a little too intellectual or just plain logical. The lack of heart behind what they say and think can be frustrating to more personal communicators.
Although Mercury in Gemini people are generally interested and interesting speakers, they can also be quite detached, easily discarding or ignoring more personal issues. They don’t get attached to their opinions and ideas for too long, and the result is a changeability and coolness that can be frustrating to others. On the other hand, their curiosity and willingness to adapt to the environment around them often endears them to others. Because they possess versatile minds, you won’t have much of a problem convincing them to change their minds.
Mercury in Gemini natives can be smooth talkers, even a little deceptive, although this is generally not with cruel intent. It’s done, usually, with a sense of humour. In fact, it’s more of a mental exercise than anything. They are able to quickly spot human weaknesses and then play around with them.
Decision-making is generally done quickly and well. They have fun with words, they are good on the phone, and they make engaging speakers. They communicate with a strong sense of fun, and they can “speak to” people from all walks of life with equal ease.
Mercury in Gemini natives often possess presence of mind and will generally impress you with their wit. For the most part, it is unlikely these people will bore you! (Source).