1493. The indicative mood is used in simple, absolute declarations: as,
#arma virumque canō#, V. 1, 1, _arms and the man I sing_. #leve fit quod
bene fertur onus#, O. _A._ 4, 2, 10, _light gets the load that’s bravely
borne_.
1494. The negative used with the indicative is commonly #nōn#, _not_
(1443). For other negative expressions, see 1445-1451.
1495. Certain verbs and verbal expressions denoting ability, duty,
propriety, necessity, and the like, mostly with an infinitive, are
regularly put in the indicative, even when the action of the infinitive
is not performed.
This applies to declarations, questions, or exclamations: as, (_a._)
#possum dē ichneumonum ūtilitāte dīcere, sed nōlō esse longus#, _DN._ 1,
101, _I might expatiate on the usefulness of the ichneumon, but I do not
care to be long-winded_. #inter ferās satius est aetātem dēgere quam in
hāc tantā immānitāte versārī#, _RA._ 150, _it would be better to pass
your days in the midst of howling beasts than to live and move among
such brutish men_. (_b._) #stultī erat sperāre#, _Ph._ 2. 23, _it would
have been folly to hope_. #quid enim facere poterāmus?# _Pis._ 13, _for
what else could we have done?_ (_c._) #licuit uxōrem genere summō
dūcere#, Pl. _MG._ 680, _I might have married a wife of high degree_.
#nōn potuit pīctor rēctius dēscrībere eius fōrmam#, Pl. _As._ 402, _no
painter could have hit his likeness more exactly_. (_d._) #quantō melius
fuerat prōmissum patris nōn esse servātum#, _Off._ 3, 94, _how much
better it would have been, for the father’s word not to have been kept_.
1496. The principal verbs and verbal expressions thus used are: (_a._)
#possum#, #licet#, #dēbeō#, #oportet#, #convenit#, #decet#. (_b._)
#aequum#, #aequius#, #iūstum#, #fās#, #necesse est#; #cōnsentāneum#,
#satis#, #satius#, #optābile#, #optābilius est#; #ūtilius#, #melius#,
#optimum#, #pār#, #rēctum est#; #facile#, #difficile#, #grave#,
#īnfīnītum#, #longum#, #magnum est#; #est# with the predicative
genitive, or a possessive pronoun (1237). (_c._) Similarly, but without
an infinitive, forms of #sum# with a gerund, a gerundive, or a future
participle.
1497. The imperfect of most of the above verbs and verbal expressions
often relates to action not performed at the present time: as,
#hīs aliās poteram subnectere causās; sed eundum est#, J. 3, 315, _to
these I might add other grounds; but I must go_. The context must
determine whether the imperfect relates (_a._) to action not performed
either in the present as here, or in the past as in 1495, or (_b._) to
action performed in the past: as, #sollicitāre poterat, audēbat#, _C._
3, 16, _he had at once the assurance and the ability to play the
tempter’s part_.
1498. Forms of #possum# are sometimes put in the subjunctive (1554).
Thus, #possim#, &c., often (1556), also #possem#, &c., usually of
present time (1560), less frequently of past time (1559), #potuissem#,
&c., particularly in sentences of negative import (1561), rarely
#potuerim#, &c. (1558). Sometimes also #dēbērem#, &c., of present time
(1560), #dēbuissem#, &c., chiefly in apodosis.