In Russian, capital letters are used:
1.At the beginning of a sentence: Сегодня тепло – Today it is warm.
2.With proper names: Пушкин – Pushkin; Волга – Volga; Москва – Moscow.
3.With possessive adjectives (containing the suffix -ин): Катина книга – Kate's book, Сашин телефон - Sasha's telephone.
4.With the pronoun Вы – you (customarily capitalized in correspondence).
Capital letters are not used for:
1.Days of the week and names of the months: среда – Wednesday; январь – January.
2.Names of nationalities and languages: американец - an American, француз - a Frenchman, французский язык - the French language/French, русский язык - the Russian language/Russian.
3.Adjectives derived from proper nouns (containing the suffix -ск): московские улицы – the Moscow streets, парижское кафе - a Parisian cafe; except when they enter into a proper noun: улица Московская – Moscow street, Казанский вокзал - Kazan railway station.
4.The pronoun я – I.
In compound proper names, as a rule, only the first member is capitalized: Чёрное море – Black Sea; Атлантический океан – Atlantic Ocean
Except when:
1.The second member is also a proper name: Южная Америка – South America.
2.Referring to high-ranking agencies: Верховный Суд – Supreme Court; Совет Безопасности – Security Council.