[1123.] The vocative nominative or vocative proper is sometimes accompanied by ō, but only in impassioned addresses: as, ō fortūnāte adulēscēns, Arch. 24, oh thou thrice blest youth; also by prō in addresses to gods, by eho and heus in calls on men. Rarely by au, ehem, hem, ē̆heu, eia or heia, iō.
[THE ACCUSATIVE.]
[1124.] The accusative is used primarily with verbs, or with expressions equivalent to verbs. The relations expressed by the accusative are all of one general kind; but they vary somewhat, according to the nature of the verb.
[1125.] I. With most verbs, the accusative either (a.) denotes that which is affected or apprehended, or is produced by the action of the verb ([1132]); or, less frequently (b.) it repeats the meaning of the verb in the form of a substantive ([1140]).
Such accusatives, called accusatives of the Object, are never attended by a preposition, and become nominative in the passive construction.
[1126.] II. With some verbs, the accusative denotes (a.) extent or duration ([1151]); with others it denotes (b.) aim of motion ([1157]).
Both these accusatives sometimes have their places taken by a prepositional expression, or by an adverb; in the passive construction, they are not convertible into a nominative, but remain accusative.
[1127.] Two or even three accusatives are sometimes used with one and the same verb: see [1167-1174].
[1128.] The accusative is sometimes disengaged from the verb, with which it originally stood, and used with a noun or a preposition.