clearer than Sag is normally capable of either handling or comprehending (unless, of course, the Archer's Moon or Ascendant is in Gemini).
It should be pointed out that those rare, quiet Sagittarians and Geminis who are keyed to a lower pitch (outwardly) than the large majority of Archers and Twins are seldom silent when they're together. Gemini has a way, by sheer auric vibration, of fanning the mildest Sag into a flaming spell of an unaccustomed monologue of words - sometimes happy and enthusiastic, at other times angry. In a similar manner, the Archer can stimulate a desire in the meeker (of the surface) Geminis to be more loquacious. But after these two have incited one another into conversation, they may not really listen to each other. They may appear to be listening, but actually, one is only waiting for the other to finish talking, so he (or she) can put across a contradictory opinion. A dramatic disagreement between them can get pretty noisy, with the need for a third party to referee. Or - one of the two will completely subdue the other, in which case, the subdued one will seek freedom from such restriction at the very earliest opportunity. In other words, leave. Sometimes, permanently.
Sagittarius tends more to inflict emotional blows to Gemini (although the Twins will make an attempt to hide such wounds behind a mask of cool boredom and disinterest) and Gemini is more likely to succeed in bending the Sagittarian mind into strange shapes, sometimes causing mental depression in the Jupiter person.
When these two (or four) are in harmony, through a positive Sun-Moon interchange between their birth charts, they can be fun to be around. One is always trying to top the other, and they'll also help each other over the rough spots, finding ways to express themselves, and to communicate, which is like a private language between them.
Often, Sag and Gemini will speak to each other's minds and hearts through music, poetry, or art - or even body language (which is a very valid form of communication, and can be most eloquent). They reach out toward one another over waves of invisible enthusiasm and excitement… dreaming impossible dreams together… looking for four-leaf clovers… and finding then surprisingly often (thanks to Jupiter luck, and Mercury visual alertness)… reflecting, in their eyes, a soul comprehension of the mutual need and desire to imitate which all polarities influenced by the 7-7 Sun Sign Pattern recognize, somehow sensing that they are opposites, seeking to blend into completeness through communion with each other.