In English, gender (= род) depends on the fact that a noun is a male, female, both or neither. So, we can put all nouns into 4 different classes:
masculine (boy, actor, man - servant, drake)
feminine (girl, actress, maid - servant, duck)
neuter (book, city, chair, box, tree)
dual, or common (friend, teacher, pupil, parent, cousin, baby, doctor) - in these cases we can find out about the gender when we hear the appropriate pronoun or possessive adjective.
Also, there are several exceptions to the rule:
* feminine gender (ships and cars when regarded with affection, names of countries, some abstract nouns such as victory or liberty, nouns like nature, earth or moon)
* masculine gender (horse, dog , nouns that describe strong feelings such as love, anger, despair or fear, nouns like time, sun or death)
* neuter gender (birds, fish and insects)
For more visual explanation, watch this video: