 The use of the past tense prefix ("e-"), the so-called augment, shows some variation and irregularity between verb classes.In regular (demotic) verbs in standard modern Greek, the prefix is used depending on a stress rule, which specifies that each past tense verb form has its stress on the third syllable from the last (the "antepenultimate"); the prefix is only inserted whenever the verb would otherwise have fewer than three syllables.In these verbs, the augment always appears as .