adverbial clause; also called final clause; introduced by the subordinating conjunction ἵνα, ὅπως, or ὡς (in order that); negative purpose clauses use ἵνα µή, ὅπως µή, ὡς µή or just µή (in order that...not, lest); uses the subjunctive if main verb is primary, subjunctive, optative, or imperative; uses optative if the main verb is secondary; tense shows aspect not time; translate verb as an infinitive; implies a goal and the action to achieve it