Observation
mishau it is big, large
ańakuneu it is covered with snow

The two verbs above are distinguished by their stem: the verb stem of mishau is misha- and ends in a, while that of ańakuneu  is ańakune- and ends in e. Verb endings can vary according to the form of the stem. There are six stem types for inanimate intransitive verbs (VII):

  • Stems ending in long a, i, e: mishautimiuańakuneu
  • Stems ending in short i: apishashu (apishashi+u)
  • Stems ending in pańi: pikupańu (pikupańi+u)
  • Stems ending in u(n): nipiu(n)
  • Stems ending in ukuishkumu
  • Stems ending in ntakuan

To identify a VII stem,  it is usually necessary to look at forms other than the dictionary form (third person Independent Indicative Present). The conjunct shows the stem vowel. For example, the following two verbs end in -u in the Independent, but in the Conjunct the stem vowel reappears before the -t : …it and …ut.

–> Is it an i or u stem? We can tell by adding negation.
apishashu it’s small apu apishashit it’s not small
kuishkumu the path is straight apu kuishkumut the path is not straight

related topics
Verb Stems Roots, stems and inflections
Verb Classes Verb conjugations