§ 63. Liquid verbs almost always strengthen their root in the Pres. and Imperf.; they lengthen it in the 1st Aor. act. and mid. by changing the root vowel, if α into η, if ε into ει, while ι and ν merely become long. ε as a root vowel is generally changed into α in the 1st Aor. and 1st Fut. pass., the Perf. and Pluperf. act. and pass., and the 2d Aor. and 2d Fut. throughout, and again into ο in the Perf. and Pluperf. mid.
§ 64. The above strengthening in the Pres. and Imperf. consists in doubling λ, annexing ν to μ; or, in case of ν or ρ, in adding ι to a preceding α or ε, or lengthening ι or υ. The radical ν is often dropped in Perf. and Pluperf.
§ 65. Verbs with ε followed by a pi- or kappa-mute in the root frequently neglect to strengthen it in the Pres. and Imperf.; and verbs with ε in the root preceded by a liquid, usually change it into α and ο in the same tenses as liquid verbs, except in the 1st Aor. and Fut. pass.
§ 66. Pure verbs lengthen the root vowel before a tense characteristic, also in the Perf. and Pluperf. pass. A few occasionally neglect this, and some insert σ instead.
§ 67. Verbs in μι (lexicon form instead of ω) are but another mode of conjugating pure verbs (being the only primitives of that class whose root ends in α, ε, or o) in the Pres., Imperf., and 2d Aor.; in all which tenses the union-vowel coalesces with the root vowel. They have a peculiar inflection, chiefly by reason of the Imperf. and 2d Aor. act. taking throughout the terminations of the Aorists pass. The Pres. and Imperf. reduplicate with ι the initial consonant, (prefixing simply ί if that cannot be done, and sometimes adopting other modes of strengthening,) and in the act. they lengthen the root in the Indic., α or ε into η, ο into ω. The 2d Aor. (those in υμι being factitious have not this tense) has in the act. a long vowel or diphthong throughout, except the Imperative ε or o, and the Participle.
Notes on Certain Verbs in μι.
§ 68. τίϑημι [to put] has, in the Act., 1st Aor. ἒϑηκα, Perf. τέϑεικα; ὀίὀωμι [to give] has, 1st Aor., ἒδωκα.
§ 69. εἰμί [to be] is inflected thus: εὶ [thou art], ἐστί(ν) [is], ἐσμέν, ἐστί, εἰσί(ν) [we, ye, they are], ἱσϑι [be thou], ὤν [being], etc.; the rest mostly regular. See the lexicon for these, and for ἵημι [to send], and εἰμι [to go].
§ 70. Several verbs annex σκω, ίνω, (ν)νυμι, etc., instead of μι, etc., in the Pres. and Imperf.