'ti' = 'you' (singular, i.e. just one person), in nominative case 'tebe' = you (singular) in accusative case (For example: 'I see you.' = 'Ja vidim tebe.') 'vi' = 'you' (plural, i.e. two or more persons), nominative case. The accusative case of 'vi' is 'vas' (For example: 'I see you.' = 'Ja vidim vas.'). Serbian nouns, adjectives, some numbers, and (in this particular case) pronouns change their form as they are used in sentences. They can change through seven cases and two numbers (which gives a total of 14 different forms one word can take). Personal pronouns (ja, ti, on, ona, ono, mi, vi, oni, one, ona) also undergo these changes. For example, the pronoun 'ti' ('you', singular): Nominative: ti Genitive: tebe (short form: te) Dative: tebi (ti) Accusative: tebe (te) Vocative: ti Locative: tebi (no short form) Instrumental: tobom (no short form)