οἶδα

Ancient Greek

From Proto-Indo-European *wóyde (“to have seen; to know”), from *weyd- (“to see; to know”). Compare εἶδον (eîdon, “to see”) and εἴδομαι (eídomai, “to seem”), which originate from different aspectual forms of the same verbal root. Cognates include Proto-Slavic *věděti, Old Armenian գիտեմ (gitem), Sanskrit वेद॑ (véda), Latin vīdī, and Proto-Germanic *witaną (English wit).^[1]

οἶδᾰ • (oîdă)

(transitive) to know; to be acquainted with [with accusative ‘something’]
1. (with neuter accusative plural of an adjective): have a quality in one's heart
2. (transitive) to be skilled in [with genitive ‘something’]
- Aristotle, Metaphysics, 1
  Πάντες ἄνθρωποι τοῦ εἰδέναι ὀρέγονται φύσει.
  Pántes ánthrōpoi toû eidénai orégontai phúsei.
  All humans by nature yearn to know.
(intransitive) to know how to [with infinitive ‘do something’]
(transitive, when main verb and participle have separate subjects) to know that [with accusative ‘someone else’ and accusative participle ‘does something’]
1. (intransitive, when subject of main verb and subject of participle are the same) to know that [with nominative participle ‘one does something’]
2. to know that (with accusative and then an indirect statement introduced by ὅτι (hóti) or ὡς (hōs))

Perfect: οἶδᾰ (Attic, present sense)

number		singular			dual		plural
		first	second	third	second	third	first	second	third
active	indicative	οἶδᾰ	οἶσθᾰ, οἶδᾰς	οἶδε(ν)	ῐ̓́στον	ῐ̓́στον	ῐ̓́σμεν, οἴδᾰμεν	ῐ̓́στε, οἴδᾰτε	ῐ̓́σᾱσῐ(ν)
	subjunctive	εἰδῶ	εἰδῇς	εἰδῇ	εἰδῆτον	εἰδῆτον	εἰδῶμεν	εἰδῆτε	εἰδῶσῐ(ν)
	optative	εἰδείην	εἰδείης	εἰδείη	εἰδεῖτον	εἰδείτην	εἰδεῖμεν, εἰδείημεν	εἰδεῖτε, εἰδείητε	εἰδεῖεν, εἰδείησᾰν
	imperative		ῐ̓́σθῐ	ῐ̓́στω	ῐ̓́στον	ῐ̓́στων		ῐ̓́στε	ῐ̓́στων
		active
infinitive		εἰδέναι
participle	m	εἰδώς
	f	εἰδυῖᾰ
	n	εἰδός
Notes:	This table gives Attic inflectional endings. For conjugation in dialects other than Attic, see Appendix:Ancient Greek dialectal conjugation.

Perfect: οἶδᾰ (Epic, present sense)

number		singular			dual		plural
		first	second	third	second	third	first	second	third
active	indicative	οἶδᾰ	οἶσθᾰ, οἶδᾰς	οἶδε(ν)	ῐ̓́στον	ῐ̓́στον	ῐ̓́σμεν, ῐ̓́δμεν	ῐ̓́στε	ῐ̓́σᾱσῐ(ν)
	subjunctive	εἰδῶ	εἰδῇς	εἰδῇ	εἰδῆτον	εἰδῆτον	εἰδῶμεν, εἴδομεν	εἰδῆτε, εἴδετε	εἰδῶσῐ(ν)
	optative	εἰδείην	εἰδείης	εἰδείη	εἰδεῖτον	εἰδείτην	εἰδεῖμεν, εἰδείημεν	εἰδεῖτε, εἰδείητε	εἰδεῖεν, εἰδείησᾰν
	imperative		ῐ̓́σθῐ	ῐ̓́στω	ῐ̓́στον	ῐ̓́στων		ῐ̓́στε	ῐ̓́στων
		active
infinitive		εἰδέναι, ῐ̓́δμεναι, ῐ̓́δμεν, ῐ̓δέμεν
participle	m	εἰδώς
	f	εἰδυῖᾰ, ῐ̓δυῖᾰ
	n	εἰδός
Notes:	Dialects other than Attic are not well attested. Some forms are based on conjecture. Use with caution. For more details, see Appendix:Ancient Greek dialectal conjugation.

Pluperfect: ᾔδειν (Attic, imperfect sense)

number		singular			dual		plural
		first	second	third	second	third	first	second	third
active	indicative	ᾔδειν, ᾔδη	ᾔδεις, ᾔδησθᾰ	ᾔδει(ν)	ᾖστον, ᾔδετον	ᾔστην, ᾐδέτην	ᾖσμεν, ᾔδεμεν	ᾖστε, ᾔδετε	ᾖσᾰν, ᾔδεσᾰν
Notes:	This table gives Attic inflectional endings. For conjugation in dialects other than Attic, see Appendix:Ancient Greek dialectal conjugation.

Pluperfect: ᾔδεεν (Epic, imperfect sense)

number		singular			dual		plural
		first	second	third	second	third	first	second	third
active	indicative	ᾔδεεν, ᾔδειν, ἠείδειν, ᾔδεᾰ, ᾔδη, ἠείδη	ᾔδεες, ᾔδεις, ἠείδεις, ᾔδεᾰς, ᾔδης, ἠείδης, ᾔδησθᾰ	ᾔδεε(ν), ᾔδει(ν), ἠείδει(ν), ᾔδη, ἠείδη	ᾔδετον	ᾐδέτην	ᾔδεμεν	ᾔδετε	ῐ̓́σᾰν, ᾔδεσᾰν
Notes:	Dialects other than Attic are not well attested. Some forms are based on conjecture. Use with caution. For more details, see Appendix:Ancient Greek dialectal conjugation.

Pluperfect: ᾔδειν (Koine, imperfect sense)

number		singular			dual		plural
		first	second	third	second	third	first	second	third
active	indicative	ᾔδειν	ᾔδεις	ᾔδει(ν)			ᾔδεμεν, ᾔδειμεν	ᾔδετε, ᾔδειτε	ᾔδεσᾰν, ᾔδεισᾰν

number		singular			dual		plural
		first	second	third	second	third	first	second	third
middle	indicative	εἴσομαι	εἴσῃ, εἴσει	εἴσεται	εἴσεσθον	εἴσεσθον	εἰσόμεθᾰ	εἴσεσθε	εἴσονται
middle	optative	εἰσοίμην	εἴσοιο	εἴσοιτο	εἴσοισθον	εἰσοίσθην	εἰσοίμεθᾰ	εἴσοισθε	εἴσοιντο
					middle
infinitive					εἴσεσθαι
participle	m				εἰσόμενος
	f				εἰσομένη
	n				εἰσόμενον
Notes:	This table gives Attic inflectional endings. For conjugation in dialects other than Attic, see Appendix:Ancient Greek dialectal conjugation.

number		singular			dual		plural
		first	second	third	second	third	first	second	third
middle	indicative	εἴσομαι	εἴσεαι, εἴσῃ	εἴσεται	εἴσεσθον	εἴσεσθον	εἰσόμε(σ)θᾰ	εἴσεσθε	εἴσονται
middle	optative	εἰσοίμην	εἴσοιο	εἴσοιτο	εἴσοισθον	εἰσοίσθην	εἰσοίμε(σ)θᾰ	εἴσοισθε	εἰσοίᾰτο
					middle
infinitive					εἴσεσθαι
participle	m				εἰσόμενος
	f				εἰσομένη
	n				εἰσόμενον
Notes:	Dialects other than Attic are not well attested. Some forms are based on conjecture. Use with caution. For more details, see Appendix:Ancient Greek dialectal conjugation.

^ Beekes, Robert S. P. (2010), “οἶδα”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 1053