397. The accusative has the following special uses.
a. The accusative is found in a few adverbial phrases (Adverbial Accusative).
at that time
id (istuc) aetātis
at that age
id (quod) genus
of that (what) sort
(perhaps originally nom.)
on my part
in a great measure
for the most part
virīle (muliebre) secus
of the male (female）sex
(probably originally in apposition)
(as to which, if)
b. The so-called synecdochical or Greek Accusative, found in poetry and later Latin, is used to denote the part affected.
Caput nectentur. (Aen. 5.309)
Their heads shall be bound.
(they shall be bound about the head)
ārdentīs oculōs suffectī sanguine et īgnī (id. 2.210)
their glaring eyes bloodshot and blazing with fire
(suffused as to their eyes with blood and fire)
nūda genū (id. 1.320)
with her knee bare (bare as to the knee).
Note— This construction is also called the Accusative of Specification.
c. In many apparently similar expressions the accusative may be regarded as the direct object of a verb in the middle voice (§ 156.a).
Inūtile ferrum cingitur. (Aen. 2.510)
He girds on the useless steel.
nodō sinūs collēcta fluentīs (id. 1.320)
having her flowing folds gathered in a knot
Umerōs īnsternor pelle leōnis. (id. 2.722)
I cover my shoulders with a lion's skin.
d. The accusative is used in exclamations.
Ō fortūnātam rem pūblicam!
O fortunate republic!
[cf. Ō fortūnāta morte (Phil. 14.31) O, happy death! (§ 339.a)]
Ō mē īnfēlīcem! (Mil. 102)
Oh, unhappy I!
Ah, wretched me!
Ēn quattuor ārās! (Ecl. 5.65)
Lo, four altars!
Ellum! (= em illum)
There he is! [Cf. § 146.a, Note 2]
Eccōs! (= ecce eōs)
There they are, look at them!
Prō deum fidem!
(O protection of the gods!)
Hōcine saeclum! (Ter. Ad. 304)
O this generation!
Huncine hominem! (Verr. 5.62)
This man, good heavens!
Note 1— Such expressions usually depend upon some long-forgotten verb. The substantive is commonly accompanied by an adjective. The use of -ne in some cases suggests an original question, as in quid? (What? Why? Tell me.)
Note 2— The omission of the verb has given rise to some other idiomatic Accusatives.
salūtem (sc. dīcit)
[in addressing a letter]
mē dīus fidius (sc. adiuvet)
so help me heaven
(the god of faith)
Unde mihī lapidem? (Hor. S. 2.7.116)
Where can I get a stone?
Quō mihi fortūnam? (Hor. Ep. 1.5.12)
Of what use to me is fortune?
[No verb thought of.]
e. The subject of an infinitive is in the Accusative.
Intellegō tē sapere. (Fam. 7.32.3)
I perceive that you are wise.
Eās rēs iactārī nōlēbat. (B. G. 1.18)
He was unwilling that these matters should be discussed.
Note— This construction is especially common with verbs of knowing, thinking, telling, and perceiving (§ 580).
f. The Accusative in later writers is sometimes used in apposition with a clause.
Dēserunt tribūnal ... manūs intentantēs, causam discordiae et initium armōrum. (Tac. Ann. 1.27)
They abandon the tribunal shaking their fists—a cause of dissension and the beginning of war.
Note— This construction is an extension (under Greek influence) of a usage more nearly within the ordinary rules, such as:
Eumenem prōdidēre Antiochō, pācis mercēdem. (Sall. Ep. Mith. 8)
They betrayed Eumenes to Antiochus, the price of peace.
[Here Eumenes may be regarded as the price, although the real price is the betrayal.]