Herbert Weir Smyth, A Greek Grammar for Colleges

VERBAL ADJECTIVES IN -τέος

[*] 2149. Verbal adjectives in -τέος express necessity. They admit two constructions:

1. The personal construction (-τέος, -τέα_, -τέον), passive in meaning, and emphasizing the subject.

2. The (more common) impersonal construction (-τέον, -τέα^, 1052), practically active in meaning, and emphasizing the action.

Both constructions are used with the copula εἰμί, which may be omitted. The agent—the person on whom the necessity rests— is expressed, if at all, by the dative (never by ὑπό and the genitive).

[*] 2150. Verbal adjectives from transitive verbs take the personal construction when the subject is emphasized; but the impersonal construction, when the emphasis falls on the verbal adjective itself. Verbal adjectives from intransitive verbs (that is, such as are followed by the genitive or dative) take only the impersonal construction.

a. Oblique cases of verbal adjectives are rare. Thus, ““περὶ τῶν ὑ_μῖν πρα_κτέων” concerning what need be done by us” D. 6.28.

[*] 2151. The Personal (Passive) Construction.—The personal verbal in -τέος is used only when the verb from which it is derived takes the accusative. The verbal agrees with the subject in gender, number, and case. The agent, if expressed, must always stand in the dative.

““ποταμός τις ἡμῖν ἐστι διαβατέος” a river must be crossed by us” X. A. 2.4.6, ““ὠφελητέα_ σοι ἡ πόλις ἐστί” the State must be benefited by you” X. M. 3.6.3, ἐμοὶ τοῦτο οὐ ποιητέον this must not be done by me (I must not do this) X. A. 1.3.15, ““οἱ συμμαχεῖν ἐθέλοντες εὖ ποιητέοι” those who would be allies must be well treated” X. M. 2.6.27, οὐ . . . τοσαῦτα ὄρη ὁρᾶτε ὑ_μῖν ὄντα πορευτέα; do you not see such high mountains that must be traversed by you? X. A. 2.5.18.

[*] 2152. The Impersonal (Active) Construction.—The impersonal verbal stands in the neuter nominative, usually singular (-τέον), rarely plural (-τέα^). Its object stands in the case (genitive, dative, or accusative) required by the verb from which the verbal adjective is derived; verbs taking the genitive or dative have the impersonal construction only. The agent, if expressed, must always stand in the dative.

““τῷ ἀδικοῦντι δοτέον δίκην” the wrong-doer must suffer punishment” P. Euth. 8c, ““πιστὰ καὶ ὁμήρους δοτέον καὶ ληπτέον” we must give and receive pledges and hostages” X. H. 3.2.18, ““τὸν θάνατον ἡμῖν μετ᾽ εὐδοξία_ς αἱρετέον ἐστίν” we must prefer death with honour” I. 6.91, ““πειστέον πατρὸς λόγοις” I must obey my father's commands” E. Hipp. 1182, πειστέον τάδε (σοί) thou must obey in this S. Ph. 994 (distinguish πειστέον ἐστί σε one must persuade thee), ““φημὶ δὴ βοηθητέον εἶναι τοῖς πρά_γμασιν ὑ_μῖν” I say that you must render assistance to the interests at stake” D. 1.17, τοὺς φίλους εὐεργετητέον, τὴν πόλιν ὠφελητέον . . ., τῶν βοσκημάτων ἐπιμελητέον you must do good to your friends, benefit your State, take care of your flocks X. M. 2.1.28, ““ἡμῖν ξύμμαχοι ἀγαθοί, οὓς οὐ παραδοτέα τοῖς Ἀθηναίοις ἐστίν” we have serviceable allies, whom we must not abandon to the Athenians” T. 1.86, ἐψηφίσαντο . . . πολεμητέα εἶναι they voted that they must go to war 1. 88.

a. Since the impersonal construction is virtually active, and hence equivalent to δεῖ with the accusative and infinitive (active or middle), the agent sometimes stands in the accusative, as if dependent on δεῖ. The copula is (perhaps) always omitted when the agent is expressed by the accusative. Thus, τὸν βουλόμενον εὐδαίμονα εἶναι σωφροσύνην διωκτέον καὶ ἀσκητέον (= δεῖ διώκειν καὶ ἀσκεῖν) it is necessary that the man who desires to be happy should pursue and practice temperance P. G. 507c.