Core Principles
Predominant Influence of the First Element: The gender of most compound nouns is determined by the first word. For example, "tire-bouchon" (corkscrew) is masculine because "tire" (pull) is masculine.
Notable Exceptions: Certain compound nouns deviate from this rule. "Porte-fenêtre" (French window) is feminine despite "porte" (door) being feminine, inheriting its gender from "fenêtre" (window).
Invariant Compounds: Some compounds remain unchanged in gender and number. "Un faire-part" (announcement) is always masculine singular.
Specific Cases and Examples
Noun + Noun: "Lave-vaisselle" (dishwasher) is masculine, following "lave" (wash). "Cure-dent" (toothpick) is masculine because "cure" (cleaning) is masculine.
Verb + Noun: "Couvre-lit" (bedspread) is masculine, taking after "couvre" (cover). "Portemanteau" (coat rack) is masculine, dictated by "porte" (carry).
Adjective + Noun: "Sourde-muette" (deaf-mute) is feminine, agreeing with "sourde" (deaf). "Haute-couture" (high fashion) is feminine, following "haute" (high).
Preposition + Noun: "Après-midi" (afternoon) is masculine, despite "midi" (noon) being feminine.
Verb + Verb: "Savoir-faire" (know-how) is masculine, typically aligning with the first verb.
Adverb + Noun: "Contre-proposition" (counter-proposal) is feminine, influenced by "proposition" (proposal).
Verb + Preposition: "Essuie-tout" (paper towel) is masculine, determined by "essuie" (wipe).
Color + Color: "Bleu-gris" (blue-gray) functions as a masculine adjective.
Compound Nouns with "à": "Arbre à chat" (cat tree) literally translates to "tree for cat," showcasing possession.
Gendered Professions
Compound nouns denoting professions often have distinct masculine and feminine forms. "Brocanteur" (male second-hand goods dealer) becomes "brocanteuse" in its feminine form.
Pluralization
Compound nouns typically form plurals by adding an 's' to the end, regardless of gender: "garde-fou" (railings) becomes "garde-fous".
Unchanging Expressions
Certain expressions maintain their form regardless of the subject's gender. For example, "s'asseoir en tailleur" (to sit cross-legged) and "agrandir à vue d'œil" (to grow visibly) remain constant.
Exceptions and Nuances
"Pèse-lettre" (letter scale) is masculine, contradicting the usual rule, as "lettre" (letter) is feminine.
Newly coined or borrowed terms may not strictly adhere to established gender rules.
Key Takeaway
While the first element generally dictates the gender of French compound nouns, exceptions and specific cases necessitate careful consideration of the individual words and their interplay within the compound structure.
