Which grammatical cases were regularly used in Classical Latin?

Classical Latin regularly used six grammatical cases in the declension of nouns and adjectives:

• Nominative: used for the subject of a verb.
• Vocative: used for the person being addressed.
• Genitive: used to express relations such as possession.
• Dative: used to indicate the indirect object (corresponding to the English preposition "to").
• Accusative: used for the direct object of a verb.
• Ablative: used to indicate relations such as separation, source, means, or agency.1

While these six cases were standard, Classical Latin also retained traces of a seventh case, the locative, in certain declensional classes of nouns.1