Case is a special grammatical category of a noun, pronoun, adjective, participle or numeral whose value reflects the grammatical function performed by that word in a phrase, clause, or sentence. In some languages, nouns, pronouns, adjectives, determiners, participles, prepositions, numerals, articles and their modifiers take different inflected forms depending on what case they are in. As a language evolves, cases can merge (for instance, in Ancient Greek, the locative case merged with the dative), a phenomenon formally called syncretism. 

English has largely lost its case system, although personal pronouns still have three cases that are simplified forms of the nominative, accusative and genitive cases: subjective case (I, you, he, she, it, we, they, who, whoever), objective case (me, you, him, her, it, us, them, whom, whomever) and possessive case (my, mine; your, yours; his; her, hers; its; our, ours; their, theirs; whose; whosever). Forms such as "I", "he" and "we" are used for the subject ("I kicked the ball"), whereas forms such as "me", "him" and "us" are used for the object ("John kicked me"). 

Languages such as Sanskrit, Ancient Greek, Latin, Armenian, Hungarian, Tibetan, Czech, Slovak, Turkish, Tamil, Romanian, Russian, Polish, Serbo-Croatian, Estonian, Finnish, Icelandic, Ukrainian, Lithuanian, Basque, Esperanto and the majority of Caucasian languages have extensive case systems, with nouns, pronouns, adjectives, and determiners all inflecting (usually by means of different suffixes) to indicate their case. The number of cases differs between languages: German and Icelandic have four; Turkish, Latin and Russian each have at least six; Armenian, Czech, Polish, Serbian, Croatian, Ukrainian, and Lithuanian have seven; Sanskrit has eight; Estonian and Finnish have fifteen, Hungarian has eighteen and Tsez has sixty-four.
What about Tsez?
Tsez has sixty-four