one proposal of the Navajo verb template (Young & Morgan 1987). Edward Sapir and Harry Hoijer were the first to propose an analysis of this type. A given verb will not have a prefix for every position, in fact most Navajo verbs are not as complex as the template would seem to suggest. The Navajo verb has 3 main parts: These parts can be subdivided into 11 positions with some of the positions having even further subdivisions: Although prefixes are generally found in a specific position, some prefixes change order by the process of metathesis. For example, in Navajo prefix ’a- (3i object pronoun) usually occurs before di-, as in adisbąąs 'I'm starting to drive some kind of wheeled vehicle along' [ < ’a- + di- + sh- + ł- + -bąąs]. However, when ’a- occurs with the prefixes di- and ni-, the ’a- metathesizes with di-, leading to an order of di- + ’a- + ni-, as in di’nisbąąs 'I'm in the act of driving some vehicle (into something) & getting stuck' [ < di-’a-ni-sh-ł-bąąs < ’a- + di- + ni- + sh- + ł- + -bąąs] instead of the expected *adinisbąąs (’a-di-ni-sh-ł-bąąs) (’a- is reduced to ’-). Metathesis is conditioned by phonological environment (Young & Morgan 1987:39). Verb stems and mode and aspect Verb stems have different forms that alternate according to aspect and tense. The alternation (ablaut) mostly involves vowels (change in vowel, vowel length, or nasality) and tone, but sometimes includes the suffixation of a final consonant. The Chiricahua verb stems below have five different forms that correspond to mode: Each mode can also occur with different aspects, such as momentaneous, continuative, repetitive, semelfactive, etc. For example, a stem can be momentaneous imperfective, momentaneous perfective, momentaneous optative, etc. The (partial) Navajo verb stem conjugation below illustrates the verb stem -’aah/-’ą́ "to handle a solid roundish object" with the same mode in different aspects: This same verb stem -’aah/-’ą́ "to handle a solid round object" has a total of 26 combinations of 5 modes and 6 aspects: Although there are 26 combinations for this verb, there is a high degree of homophony, in that there are only 7 different stem forms (-’aah, -’ááh, -’aał, -’ááł, -’a’, -á, -’ą́). To complicate matters, different verbs have different patterns of homophony: some verbs have only 1 stem form that occurs in all mode-aspect combinations, others have 5 forms, etc., and