124. The imperfect indicative, like the indicative of the other secondary tenses (see §20, footnote), places an augment at the beginning of the stem of the verb.
125. In verbs that begin with a consonant the augment consists in an ε- prefixed to the stem.
Examples: ἔλυον, I was loosing; ἐγίνωσκον, I was knowing.
126. In verbs that begin with a vowel, the augment consists in the lengthening of that vowel. But α lengthens not to long α but to η.
Examples: The imperfect of ἐγείρω is ἤγειρον; of ἀκούω, ἤκουον; of αἴρω, ᾖρον.