a perfect active participle is an important reason leading to the use of this construction (cf . §381, note 3).
LESSON LXX
§ 395. Dwell on the point that the reason for the use of the subjunctive in a cum clause and in a relative clause of description is the same (§ 389.a).
It will help the student to tell him that an indicative clause with cum fixing the time of the main action is very often preceded by tum or some other expression of time. See the first example under § 395, and § 400.I.10; II.1. Further,cum concessive is often followed by tamen, nevertheless.
§ 397.a. The ablative of specification is closely akin to the ablative of manner and shows some resemblance to that of means and of cause. It, therefore, comes under the with or by ablative relation.
§ 399. The idioms included in this and the following lessons are very common in Cæsar. Require the class to memorize them. The labor spent will be well rewarded later.
Explain that certior in certior fierī is a predicate adjective and must agree with the subject, just as certiōrem in certiōrem facere is a predicate adjective agreeing with the object.
LESSON LXXI
§ 404. Remind the class that the gerundive, ending as it does in -us, is declined like bonus, -a, -um, and agrees with its noun like any adjective.
§ 405. This article merits very careful study. Have the class memorize the examples and especially the observations under a. If these are well understood the pupils will have no trouble with the gerund and gerundive.
Point out to the class that a gerund must end in -ī, -ō, or -um, and that any other ending will mark the form in question as gerundive.
§ 406.2. Observe that the presence of a preposition forbids the use of a gerund + object.
