Register: ты and вы
ты for one person you know well, вы for everybody else — and вы changes the verb, the possessive and the imperative too.
Russian has two ways of saying 'you', and choosing wrongly is a social error rather than a grammatical one. Ты is singular and close: family, friends, children, classmates, people of your own age in an informal setting, colleagues once the ice is broken, and anybody who has explicitly offered it. Вы is the plural of both, and the polite singular for adults you do not know, older people, officials, shop assistants, hotel staff, doctors, teachers and anyone you are dealing with professionally.
The asymmetry is real and is better understood than resented. An adult says ты to a child; the child says вы to the adult, though inside the family this relaxes quickly. Peers of similar age and status normally move to ты within minutes. A manager may say ты while the employee says вы, and this is unremarkable rather than rude. If you are unsure, begin with вы: it is never offensive, whereas an unwelcome ты can be. The offer to switch always comes from the older or more senior party, in the formula Дава́йте на ты.
The whole grammar changes with the choice. The verb takes the plural form: Ты чита́ешь becomes Вы чита́ете. The possessive becomes ваш instead of твой: твой дом, ваш дом. The imperative takes -те: Скажи́, Скажи́те. Polite formulas multiply accordingly — Не могли́ бы вы, Бу́дьте добры́, Бу́дьте любе́зны, Извини́те instead of Прости́, Пожа́луйста in the same place. When вы addresses one person the verb is still plural; only the meaning is singular.
The capitalised Вы is a convention of formal letters, official documents and job applications, addressed to a single reader. In ordinary prose, email, texting and fiction it is lowercase вы, and capitalising it elsewhere reads as obsequious or ironic. Unlike Italian Lei, which uses third-person verb forms, Russian вы is simply the second-person plural, so there is nothing new to conjugate — only a social judgement to make.
Examples
- Ты студе́нт? — Да, я студе́нт. Are you a student? — Yes. (informal, to one person) Listen in Russian: Slow in Russian: Ты студе́нт? — Да, я студе́нт.
- Вы студе́нт? — Да, я студе́нт. Are you a student? — Yes. (polite singular, or plural) Listen in Russian: Slow in Russian: Вы студе́нт? — Да, я студе́нт.
- Скажи́те, пожа́луйста, где здесь метро́? Excuse me, where is the metro here? — the polite imperative in -те Listen in Russian: Slow in Russian: Скажи́те, пожа́луйста, где здесь метро́?
- Не могли́ бы вы мне помо́чь? Could you possibly help me? Listen in Russian: Slow in Russian: Не могли́ бы вы мне помо́чь?
- Э́то твой дом и́ли ваш? Is this your house, or your family's? Listen in Russian: Slow in Russian: Э́то твой дом и́ли ваш?
- Дава́йте на ты. Let's switch to ты. — the offer comes from the older or senior person Listen in Russian: Slow in Russian: Дава́йте на ты.