δεῖ

Impersonal forms of δέω (déō, “to bind”).

δεῖ • (deî)

1. (with personal accusative and infinitive) it behoves one to, it is necessary to, one must
   • 800 BCE – 600 BCE, Homer, Iliad 9.337
   • 522 BCE – 443 BCE, Pindar, Olympian Ode 6.48
   • 343 BCE, Demosthenes, On the False Embassy 235
   • 497 BCE – 405 BCE, Sophocles, Ajax 556
   • 428 BCE, Euripides, Hippolytus
   • 430 BCE – 354 BCE, Xenophon, Anabasis 3.4.35
   • 430 BCE – 354 BCE, Xenophon, Oeconomicus 7.20
   • 484 BCE – 425 BCE, Herodotus, 1 8
   • 406 BCE, Sophocles, Oedipus at Colonus 570
   1. (with impersonal accusative and infinitive)
      • 460 BCE – 395 BCE, Thucydides, 5 26
      • 460 BCE – 420 BCE, Herodotus, Histories 2.161
      • 429 BCE, Sophocles, Oedipus the King 825
   2. (when used in absolute an infinitive may be supplied)
      • 406 BCE, Sophocles, Oedipus at Colonus 1442
      • Philetaerus Comicus, Ἀταλ. 1
2. (with impersonal genitive) there is need of, there is wanting
   • 525 BCE – 455 BCE, Aeschylus, Prometheus Bound 870
   • 470 BCE, Aeschylus, The Suppliants 407
   1. (with a personal dative)
      • 458 BCE, Aeschylus, Agamemnon 848
      • 431 BCE, Euripides, Medea 565
      • 460 BCE – 395 BCE, Thucydides, History of the Peloponnesian War 1.71
   2. (with personal accusative)
      • 525 BCE – 455 BCE, Aeschylus, Prometheus Bound 86
      • c. 440 BCE, Euripides, Rhesus 837
   3. (nominative, rare)
      • 423 BCE, Euripides, The Suppliants 594
      • 480 BCE – 411 BCE, Antiphon of Rhamnus, Collected Works 142.43
3. (neuter participle, absolute use) it being needful, fitting
   • 428 BCE – 347 BCE, Plato, Protagoras 355D
   • 361 BCE, Demosthenes, Against Midias 90
   • 423 BCE, Aristophanes, The Clouds 989
   • 484 BCE – 425 BCE, Herodotus, 3 65
   • 46 CE – 120 CE, Plutarch, Fabius Maximus 9
   • 200 BCE – 118 BCE, Polybius, The Histories 2.37.5

• Present indicative: δεῖ (deî)
• Present subjunctive: δέῃ (déēi), δῇ (dêi)
• Present optative: δέοι (déoi)
• Present infinitive: δεῖν (deîn)
• Present participle: δέον (déon), δεῖν (deîn)
• Imperfect: ἔδει (édei), ἔδεε (édee) (Ionic)
• Future: δεήσει (deḗsei)
• Aorist: ἐδέησε (edéēse)