Most inanimate indeclinable nouns belong to the middle family, regardless of the value and end in a vowel. The word "depot", "highway", "jury", "interview", "coat", "movie", "alibi", "cocoa", "puree" is neuter. For example, locomotive depot, an interesting interview alibi.
Among these nouns there are several words that have kind of motivated by the value of the generic concept or the old forms. Avenue - street, female; kohlrabi - cabbage, feminine; coffee - drink, then men's; salami - sausage, female; penalty, free kick, male; Sirocco - wind, men's. For example, fresh kohlrabi, hot coffee, delicious salami.
The gender of a noun, calling persons depends on real sex. If the word calls men, these masculine nouns and pronouns (dandy). If female, then feminine nouns (Frau, lady).
Nouns naming persons in the profession are masculine, although you can call and females: attache, entertainer, Maestro. For example, the military attache Petrov and Sidorov special attaché, an experienced entertainer Izmailov and well-known entertainer Orlov.
The names of animals and birds usually refers to the masculine: zebu, a Hummingbird, a chimpanzee. But if in the context of the noun indicates a female, the word refers to the feminine: a chimpanzee feeding a baby. And only in a few words the genus is a generic concept: iwashi - herring, feminine; tsetse - fly, is feminine. For example, delicious iwashi, threat tsetse.
Gender of undeclined nouns is determined by the nature of a common noun, a nounacting as a generic term. For example, Sunny Sochi - the city, the masculine; deep, on the lake, average; hot Gobi desert, female.
Indeclinable nouns are among slozhnosochinennyh words. The genus of such abbreviations is determined by the main word in the complete name. For example: UN (the United Nations, the feminine gender) adopted a resolution RIA (Russian information Agency, the average) reported. But to this rule there are exceptions: TASS is authorized to declare. Although the key word here is Agency.