The way you talk and listen is one of the first things new people notice — and as much as your rising sign affects that, you actually have your Mercury sign to thank for your gift of gab or receptive listening skills.
Beyond giving you some context into how you talk and think, your Mercury sign can help you identify potential BFFs. Comparing your respective Mercury placements with people may give you a better idea of how you'll get along. If you have Mercury in chatty Gemini, for example, you might mesh well with someone a little quieter, but just as intellectually curious as you are — like someone with Mercury in Virgo. (Although, it should be said, having misaligned Mercury signs is not a good enough excuse to dismiss someone you've just met.)
If you aren't sure what your Mercury sign is, check your birth chart online. You can also narrow it down by following this astrological rule of thumb: Your Mercury sign is either the same as your sun sign, the sign that precedes your sun sign, or the one that follows your sun sign. Ahead, learn more about what each Mercury sign means.