What it does well
Genuinely open-minded and hard to discourage. Says the thing nobody else will.
Fire · Mutable · ruled by Jupiter
☿ Mercury in Sagittarius
Mercury in Sagittarius means the mercury stood in Sagittarius at the moment you were born. Mercury meets sagittarius: thinking and speech — how you process and explain. It moves through a sign in about 30.3 days, which is short enough for the placement to be personal.
How many people share this
Mercury spends 30.3 days in a sign
30.3 days
in each of the twelve signs, so a full circuit takes
1 years.
8.33%
of birth dates fall under any one sign for this
placement — one twelfth, by construction.
Personal
Changes fast enough to differ between siblings.
Fast enough that two people born the same week can differ here, which is what makes it worth reading at all. Compare every planet’s speed →
Mercury governs thinking and speech — how you process and explain. In Sagittarius, that function takes on expansion, honesty and appetite for the unfamiliar — a Mutable Fire expression ruled by Jupiter.
Where it strains
Says it without checking whether it needed saying, and leaves before the consequences land.
Reading a placement properly
Mercury in Sagittarius describes a function in a style. It says nothing yet about where that plays out — for that you need the house, and the house needs a birth time. A placement read without its house is half a sentence.