The document discusses case systems in different languages including Pitta-Pitta, Latin, and English. It provides examples of:
1) The case system in Pitta-Pitta which uses affixes to mark grammatical relations and has nominative, ergative, accusative, dative, purposive, locative, and other cases.
2) The complex case system in Latin involving three declensions marked by suffixes to indicate case, number, gender, and other categories.
3) The evolution of the case system in English from Old English to modern English, where it is largely restricted to pronouns and the genitive possessive marker.