In Russian nouns have three gender groups- masculine, feminine or neuter. Depending on the gender the endings of the nouns change. Knowing the gender is especially useful when it comes to learning cases and how nouns change accordingly. Determining gender might be tricky, the obvious ones are for people, like, муж – husdband, жена – wife, сын – son, дочь – daughter. However, after that it gets harder. Both nouns for living and non-living objects can be masculine, feminine or neuter for example карандашь – pensil, ручка – pen, сердце – heart. Sometimes there it is hard to understand the logic of why certain nouns are allocated to their group. For example Земля – Earth is female but Солнце – Sun is neuter. The easiest way to determine the gender is according to its endings.
Masculine is the most complicated and has a lot of exceptions. The standard ending for masculine nouns are referred to in Russian as zero ending, when the noun ends with a constant. For example отец – farther, стул – chair, стол – table. Another common ending is - Й; музей -museum, самурай – samurai, hero – герой. A third option is the soft sound - Ь; словарь - dictionary. Then there are the exceptions. - A, - E, - Я ending are sometimes used for masculine nouns; мужчина – man, дядя – uncle, кофе – coffee.
Females have - А,-Я, -Ь endings, such as: мать – mother, сестра – sister, свечка – candle, луна – moon, ночь – night, дочь – daughter, вишня – cherry, лилия – lily.
Neuter endings have - О, - Е such as: дерево – tree, кольцо – ring, окно – window, яицо – egg, лицо – face, солнце – sun. A rare ending is - Я; like время -time.
So to sum up, there are a lot of exceptions, however the more words you learn, the easier it gets. But for now all that needs to be remembered is:
Masculine - zero ending,-й, -ь, –а, -я.
Feminine - -а, -я, -ь.
Neuter - -о,-е, -я
After learning which gender a noun is, it’s easier to allocate the noun to it declension, from that you can determine how nouns change per case.