Verbal Vowel Assimilation (part 2)

Let's take a look at the verb stems alone:

Indi.: мεн-, нοιмε-, οιδα-, παнxο-, δεικн-
Con.: мεнe-, нοιмe-, οιδά-, παнxό-, δεικнύ-
Opt.: мεнε͂ι-, нοιмε͂ι-, οιδᾶι-, παнxο͂ι-, δεικнῦι-

There are five different verb types: verbs without a thematic vowel and ε-, α-, o- and υ-thematic verbs. υ-thematic vowels do not appear in the indicative.

In the coniunctive, the thematic vowel is prolongued. ε>e; α>ά; ο>ό, υ>ύ.
Verb stems without a thematic vowel get an -e- added.

In the optative, -ε͂ι- is added to the verb stem.