Allen and Greenough's New Latin Grammar, section 410

Heavy Construction

The Allen and Greenough is still under construction; so some links may not work quite the way you would expect.

410.

The deponents útor, fruor, fungor, potior, vescor, with several of their compounds,[1][These are abútor, deútor (very rare), défungor, défruor, perfruor, perfungor.] govern the Ablative: -

útar vestrá benígnitáte (Arch. 18), I will avail myseif of your kindness.
ita mihi salvá ré públicá vóbíscum perfruí liceat (Cat. iv. 11), so may I enjoy with you the state secure and prosperous.
fungí inání múnere (Aen. vi. 885), to perform an idle service.
auró hérós potitur (Ov. M. vii. 156), the tero takes the gold.
lacte et feríná carne vescébantur (Iug. 89), they fed on milk and game.

NOTE: This is properly an Ablative of Means (instrumental) and the verbs are really in the middle voice (§156. a). Thus útor with the ablative siguifies I employ myself (or avail myself) by means of, etc. But these earlier meanings disappeared from the language, leaving the construction as we find it.

a. Potior sometimes takes the Genitive, as always in the phrase potíri rérum, to get control or be master of affairs (§35*. a):

t*lus Galliac scsi potirt posse spirant (B. G. i. 8), they hope they can get possession of the whole of *aul.

NOTE 1: In early Latin, these verbs are sometimes transitive and take the accusative: IfinctuS est efficium (Tar. Ph. 281), he performed the pert, eta. ille patria potitur commoda (Tar. Ad. 871), he enjoys his ancestral estate.

NOTE 2: The Gerundive of these verbs is used personally in the passive as if the verb were transitive (but at. §500.3): as,-Hiracbo- omnia jitenda ae possidenda tr* diderat (verr. ii. 46), he had given over everything to Leraclius for his use and possession (to be used and possessed).