From Earth, Mercury and Venus stay on the Sun's side of the sky because their orbits lie inside Earth's orbit.
Smaller orbits, a limited view
Both planets travel around the Sun closer in than Earth does. Looking from our outer orbit, we see them to one side of the Sun or the other, but never on the opposite side of the sky.
Morning or evening appearances
When visible, Mercury and Venus are often seen before sunrise or after sunset. Sometimes they appear too close to the Sun to pick out in its glare. Their visibility changes over time.
What this explains on a chart
A typical birth chart records positions from Earth's viewpoint, so Mercury and Venus stay relatively near the Sun around its circle. This follows from the orbits. It is not, by itself, an explanation of someone's personality or future.
A few common questions
Must Mercury and Venus be in the same sign as the Sun?
No. They stay relatively close to the Sun, but can fall in other nearby signs. Check the labels on the chart.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.