Natal house is the sign where a planet was originally placed during your time of birth.
If Venus was placed in Gemini in your personal horoscope, then during transit, Mercury forming conjunction (in Gemini), sextile (aspect of 60° which are Aries and Leo in this case), square (aspect of 90° which are Virgo and Pisces here), trine (aspect of 120° which are Libra and Aquarius here), opposition (aspect of 180° which is Sagittarius here) are discussed in this article.
Conjunction is transiting through same sign as in birth chart, sextile is transiting 3rd or 11th house, trine is transiting 5th or 9th house, opposition is transiting 7th house from natal sign.
Transit Mercury conjunct Natal Venus : Artistic, romantic, social and business communications characterize this transit. This transit indicates intellectual appreciation of music, poetry, beauty and emotions. The native is interested in beautifying the work environment. The native can advertise successfully and can become an expert in public relations. The native is a charming personality and exhibits greater wit, charm, humor and diplomacy in social interaction. The native adorns himself according to demand of situation. Under adverse aspects to this transit the native is more showy and superficial in social communications.
Transit Mercury Sextile Natal Venus : Encouraging and harmonious social contacts characterize this transit. The native is interested in leisure pursuits like attending parties, visiting places of amusement, art exhibitions and reading for amusement etc. A right time to express love feelings to someone you like and for romance trips. The native can appreciate the dresses and personality of others with an appreciable degree of grace, diplomacy and tact.
Transit Mercury Square Natal Venus : Emotional hypersensitivity and difficulties in social and romantic communications characterize this transit. The native is mentally in-disciplined. Favoritism, emotional likes and dislikes interfere with his logical and practical decisions. Passionate expenditure on articles of personal adornment and clothing are evident. Not a good time for asking social and business favors. This is the time to avoid unpleasant conflicts.
Transit Mercury Trine Natal Venus : Graceful and harmonious social communications and regard for feelings of others characterize this transit. The native is friendly and positive to everyone and avoids unpleasantness in relationships. A time to enjoy get together and artistic creations. The native uses tact and diplomacy in business and romantic communications. There may be trips regarding work and pleasures.
Transit Mercury opposition Natal Venus : At this time passions and intellect are opposing each other and can cause conflicts, worries and tensions. The native gives ground for issues he would have defended. The native tends to involve in meaningless gossips. The native is very sensitive to remarks and attitudes of others. Diplomacy and tact is required in business, social and personal relationships. The native should use hypocrisy in order to avoid any unpleasantness in relationships.