The Different Stems of the Verbs

The verb for to boil has three stems, which I love. Because different stems undergo various changes and they represent the early forms. So anyway, but that's fun. It looks to me like what he imagined was happening is that at some stage of the language, there was an extremely strong stress accent, which obliterated everything that came after. Um, and then the sound system had to be reorganized to fit the rules.