STEP Liddell–Scott–Jones: δεῖ

δεῖ:

subjunctive δέη, sometimes contraction δῆ (in codices of Comedy texts, as [[ 5th-6th c.BC: Aristophanes Comicus “Ranae” 265)] Refs 5th c.BC+]; ὁπόσου κα δῆ [[ “IG” 4.1484.65 (Epid.), compare “SIG” 245 G 47 (Delph.); _optative_ δέοι 5th c.BC: Thucydides Historicus 4.4 ] Refs 5th c.BC+]; infinitive δεῖ; participle δέον (see. infr. IV): imperfect ἔδει, Ionic dialect ἔδεε: future δεήσει [[ 5th c.BC: Euripides Tragicus “Hippolytus” 941, etc.] Refs 5th c.BC+]: aorist I ἐδέησε [[ 5th c.BC: Thucydides Historicus 2.77, etc.] Refs 5th c.BC+] —Impers. from δέω (A), there is need (the sense of moral obligation, properly belonging to χρή, is later, [[ 5th c.BC: Sophocles Tragicus “Philoctetes” 583, etc.): ] Refs 5th c.BC+]

__I c.accusative person et infinitive, it is needful for one to do, one must, once in [[ 8th c.BC: Homerus Epicus, τί δὲ δεῖ πολεμιζέμεναι.. Ἀργείους] Refs 8th c.BC+] why need the Argives fight? [[ 8th c.BC: Ilias Homerus Epicus “Illiad” 9.337; δ. [μ᾽] ἐλθεῖν 5th c.BC: Pindarus Lyricus “O.” 6.28, etc.] Refs 8th c.BC+]: with nominative of the pronoun, ἡγούμην.. δεῖν.. μεγαλοψυχότερος φαίνεσθαι [[ 4th c.BC: Demosthenes Orator 19.235: rarely δεῖ σ᾽ ὅπως δείξεις, ={δεῖ σε δεῖξαι}, 5th c.BC: Sophocles Tragicus “Ajax” 556, compare “Ph.” 54; δεῖ σ᾽ ὅπως μηδὲν διοίσεις 5th c.BC: Cratinus Comicus 108; (the full _construction_ in 5th c.BC: Sophocles Tragicus “Philoctetes” 77 τοῦτο δεῖ σοφισθῆναι.. ὅπως γενήσῃ)] Refs 5th c.BC+]: rarely with dative person, there is need of.. for.., θεοῖσι προσβαλεῖν χθονὶ ἄλλην δεήσει γαῖαν [[ 5th c.BC: Euripides Tragicus “Hippolytus” 941, compare 5th-6th c.BC: Xenophon Historicus “Anabasis” 3.4.35, “Oec.” 7.20: the _accusative_ _person_ is often omitted, ἐκ τῶν μανθάνειν δεῖ (i.e. ἡμᾶς) 5th c.BC: Herodotus Historicus 1.8, compare 4th-5th c.BC: Aeschylus Tragicus “Agamemnon” 567, “Eu.” 826, etc. ] Refs 5th c.BC+]