VP p.28: Many verbs have alternating stems for punctiliar vs continuous aspect, e.g. boko-l 'talk PUNCT' vs baka-m 'talk. CONT'||We now regard –l as just epenthetic, not part of any morpheme. No matter how much or little we or you call "stem", it is still true that many verbs have suppletive marking of aspect (PUNCT vs CONT) in verb roots.
