2.sg. imperative ending is used with particular verb forms. For example, the athematic second aorists. In a few days an article I've written about those will show up elsewhere on Textkit. <br /><br />In any case some other athematic verb forms (that is, they don't use a helping vowel before the ending) also take this ending, which includes several of the [face=SPIonic]-mi[/face]
verbs which are irregular enough to get written out in grammars, certain aorists, and a few second perfects.<br /><br />The ending isn't common, but the verbs that use it are.
are both very common.