Does Mercury's sign change how I think, or just how I talk? Both, in principle, and the house shifts the balance. Sign colours the mental accent; house shows where that thinking goes to work. Mercury in Aries in the 10th argues in public; the same Aries Mercury in the 4th argues across the kitchen table.
Does Mercury's sign strength change how quick I am? Yes, in the traditional frame — but read it as ease, not speed. Mercury is strong in Gemini and Virgo, the two signs it rules, and gains extra force in Virgo, its exaltation. It is weaker in Sagittarius and Pisces, its detriment, and in Leo, its fall. Strong means the words arrive ready and fluent; weak means the mind works harder at the delivery. This is interpretive tradition, not a measured skill. A 'weak' Mercury still thinks fast, and often arrives somewhere more interesting than the tidy answer.
Then what are dignity's limits? Dignity describes the planet's condition in a sign, not your intelligence, your memory or your argument win rate. Mercury in Pisces is not a dim placement; it processes by feel and by leap rather than by filing. Mercury in Virgo is not automatically right; it is fluent at editing. Dignity is a weather report for the delivery, nothing more.
What do you mean about memory, then? A chart describes filing habits, not capacity. Mercury in Virgo tends to store and index; Mercury in Pisces tends to remember the mood of the room and lose the date. The second kind does not remember less — it remembers different things. Your capacity is yours. The chart only shows what your mind reaches for first when it goes to fetch something.
Does a Saturn contact really mean I'm slow? It means you check. The verdict arrives late because it arrives tested. Pair that with a fast Ascendant ruler and you get the sharp combination: quick to speak, slow to commit.
Is Mercury retrograde in my chart a problem? No. It describes a revising mind — one that thinks twice, returns, rewrites. The people who hire editors want exactly that. It is a processing style, not a fault line.
Can I compare my Mercury with someone else's? Yes, using calculated planetary positions. The synastry chart calculator takes both sets of birth details and shows where the two Mercuries meet, and at what angle. A shared sign sector is not the same thing as a real aspect.
How often should I re-check my chart? The natal placements never move. Re-enter it only when you want to test a passing transit against your Mercury, which is where the transit chart calculator comes in.
And a framework note: Mercury readings here are interpretation within astrology, not measured psychology. The astronomy is checkable — Mercury's apparent backward motion is a line-of-sight effect. What it means for your memory or your arguments is a reading you test against your own life.