There is no rule that can help you with a random word. Still, there are some good rules that help you predict the gender of a non-random word: FEMININE nouns end in - ЖЬ/ ШЬ/ ЧЬ/ ЩЬ — hushes. Consider youself lucky to be non-native: a final soft sign is only written after hushes if the noun is feminine (no, it doesn't affect the pronunciation). Masculine nouns just end in a consonant then (нож, луч. мяч) - ОСТЬ (-есть). "ост" is a very popular suffix to create abstract noun: "возможность" (opportunity), "относительность" (relativity), "сухость" (dryness) - ЗНЬ. For example: жизнь, болезнь MASCULINE nouns end in: - ТЕЛЬ : a popular suffix for professions and other "doers": учитель (teacher), усилитель (amplifier) - АРЬ: словарь, Also, all month names are masculine (though, not all of them end in -арь) Other than that — try dictionary. If you absolutely have to guess, feminine are definitely way more numerous among commonly encountered nouns. Common masculine nouns in -Ь: день, путь, парень, огонь, камень, словарь, гость, рубль, уровень, дождь, король, отель, лагерь, корабль, медведь, конь, господь, корень, царь, зверь, спектакль, стиль, шампунь, ноготь, гвоздь, портфель, кашель, кошель, кисель, контроль, ремень, алкоголь, ноль, руль, лось, гусь, пень, автомобиль, коктейль, гриль. Also don't forget suffixed nouns. And all the months :)

Unfortunately as I was told , It has no rules . It's known by memorizing it :)

This end may be in the words of the feminine and words importing the masculine. For example: конь (masculine), мать (feminine).

If the word has got -ь ending in the singular Nominative case, it is FEMININE. If it hasn't got -ь ending in the singular Nominative case, it is MASCULINE: Грач_, мяч_, мыс_ and so on are MASCULINE. Печь, дочь, мышь, высь and so on are FEMININE.