(i.) The rich development and fine discrimination of the uses of the
subjunctive mood, especially (a) in indirect questions (based on
direct deliberative questions and not fully developed by the time of
Plautus, who constantly writes such phrases as _dic quis es_ for the
Ciceronian _dic quis sis_); (b) after the relative of essential
definition (_non is sum qui negem_) and the circumstantial _cum_ ("at
such a time as that"). The two uses (a) and (b) with (c) the common
Purpose and Consequence-clauses spring from the "prospective" or
"anticipatory" meaning of the mood. (d) Observe further its use in
subordinate oblique clauses (_irascitur quod abierim_, "he is angry
because, _as he asserts_, I went away"). This and all the uses of the
mood in oratio obliqua are derived partly from (a) and (b) and partly
from the (e) Unreal Jussive of past time (_Non illi argentum redderem?
Non redderes_, "Ought I not to have returned the money to him?" "You
certainly ought not to have," or, more literally, "You were not to").
On this interesting chapter of Latin syntax see W. G. Hale's
"Cum-constructions" (_Cornell University Studies in Classical
Philology_, No. 1, 1887-1889), and _The Anticipatory Subjunctive_
(Chicago, 1894).
(ii.) The complex system of oratio obliqua with the sequence of tenses
(on the growth of the latter see Conway, _Livy II._, Appendix ii.,
Cambridge, 1901).
(iii.) The curious construction of the gerundive (_ad capiendam
urbem_), originally a present (and future?) passive participle, but
restricted in its use by being linked with the so-called gerund (see §
32, b). The use, but probably not the restriction, appears in Oscan
and Umbrian.
(iv.) The favourite use of the impersonal passive has already been
mentioned (§ 5, iv.).
35. The chief authorities for the study of Latin syntax are:
Brugmann's _Kurze vergl. Grammatik_, vol. ii. (see § 28); Landgraf's
_Historische lat. Syntax_ (vol. ii. of the joint _Hist. Gram._, see §
28); Hale and Buck's _Latin Grammar_ (see § 28); Draeger's
_Historische lat. Syntax_, 2 vols. (2nd ed., Leipzig, 1878-1881),
useful but not always trustworthy; the Latin sections in Delbrück's
_Vergleichende Syntax_, being the third volume of Brugmann's
_Grundriss_ (§ 28).