The partner Mercury in the 7th describes
The spouse tends to be witty, articulate, intelligent, and youthful-looking — often appearing younger than their age. They value communication and mental connection. Many natives also do well in business partnerships (the 7th is the house of partners of all kinds), since Mercury rules commerce, contracts, and exchange.
Communication as the marriage glue
For this placement, talking is the relationship. Marriages thrive on conversation, humour, and shared curiosity, and struggle when communication breaks down or turns into nervous over-analysis. Mercury is exalted in Virgo and debilitated in Pisces, which sharpens or softens the intellect involved. Timing of marriage often connects to Mercury periods and to mental readiness.
Strengths and the deeper read
The gift is a partner who keeps the mind alive and a relationship that stays interesting. The growth is depth over cleverness — not letting talk replace feeling. The full picture depends on Mercury’s sign, whether it is combust (too close to the Sun), its aspects, and the Navamsa (D9).