There are three genders in Russian: masculine (he), feminine (she) and neuter (it). Usually, one can determine the noun gender by the noun ending.
Plural nouns are constructed as follows:
The word "яблоко" is an exception, the plural form is "яблоки".
The words "ДЕНЬГИ", "ОЧКИ" have only the plural forms.
Pronouns HE, SHE can serve as substitutes for both animate and inanimate nouns. The pronoun IT serves as a substitute for inanimate nouns only.