French nouns can be masculine (articles: le, un) and feminine (articles: la, une). Feminine names are usually names of females, diseases, teachings, holidays. Masculine are the names of male persons, trees, days, seasons, months, cardinal points, winds, numbers, letters, etc.
masculine: -age, -ail, -ard, -as, -at, -eau, -er, -et, -is, -isme, -ment, -oir, -ot, -ron
feminine: -ade, -aie, -aille, -aison, -ation, -ance, -asse, -ée, -elle, -esse, -ette, -ie, -iεre, -ine, -ise, -ose, -otte, -sion, -té, -tion, -tude, -ure.
The gender of a particular noun is given in the dictionary.