I Love Her, My Lover, I Love You

There are five different stem forms, which are discussed on page 224. There's something they call the incomplete, which just looks like an imperfective in every time except the present. And there's a de-verbal noun form, which is used for things that sort of stands in for things like infinitives and participle lines. In addition to that, there are different suffixes that also mark tense and aspect so you get this mix and match.