Navajo is a "verb-heavy" language – it has a great preponderance of verbs but relatively few nouns. In addition to verbs and nouns, Navajo has other elements such as pronouns, clitics of various functions, demonstratives, numerals, postpositions, adverbs, and conjunctions, among others. Harry Hoijer grouped all of the above into a word-class he called particles (i.e., Navajo would then have verbs, nouns, and particles). Navajo has no words that would correspond to adjectives in English grammar: verbs provide the adjectival functionality.
Verbs
The key element in Navajo is the verb. Verbs are composed of an abstract stem to which inflectional or derivational prefixes are added. Every verb must have at least one prefix. The prefixes are affixed to the verb in a specified order.
The Navajo verb can be sectioned into different components. The verb stem is composed of an abstract root and an often fused suffix. The stem together with a "classifier" prefix (and sometimes other thematic prefixes) make up the verb theme. The thematic prefixes are prefixes that are non-productive, have limited derivational function, and no longer have a clearly defined meaning. Examples of thematic prefixes, include the archaic yá- prefix, which only occurs on the verb stem -tééh/-tiʼ meaning "to talk" as in yáłtiʼ "he's talking". The theme is then combined with derivational prefixes that in turn make up the verb base. Finally, inflectional prefixes (which Young & Morgan call "paradigmatic prefixes") are affixed to the base – producing a complete Navajo verb.
Verb template
The prefixes that occur on a Navajo verb are added in specified more or less rigid order according to prefix type. This type of morphology is called a position class template (or slot-and-filler template). Below is a table of a recent 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 does not have a prefix for every position. In fact, most Navajo verbs are not as complex as the template might suggest: the maximum number of prefixes is around eight.
The Navajo verb is composed of a verb stem and a set of prefixes. The prefixes can be divided into a conjunct prefix set and disjunct prefix set. The disjunct prefixes occur on the outer left edge of the verb. The conjunct prefixes occur after the disjunct prefixes, closer to the verb stem. Two types of prefixes can be distinguished by their different phonological behavior.
{ | class="wikitable" frame=void style="vertical-align:top; text-align:center; white-space:nowrap;" |- | disjunct prefixes | conjunct prefixes | stem |}
The prefix complex may 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, prefix ʼa- (3i object pronoun) usually occurs before di-, as in
ʼadisbąąs "I'm starting to drive some kind of wheeled vehicle along" [ ← ʼa- + di- + sh- + ł + -bąąs].
However, when ʼa- occurs with the prefixes di- and ni-, the ʼa- metathesizes with di-, leading to an order of di- + ʼa- + ni-, as in
diʼnisbąąs "I'm in the act of driving some vehicle (into something) & getting stuck" [ ← di-ʼa-ni-sh-ł-bąąs ← ʼa- + di- + ni- + sh- + ł + -bąąs]
instead of the expected ʼadinisbąąs (ʼa-di-ni-sh-ł-bąąs) (ʼa- is reduced to ʼ-).
Although the verb template model of analysis has been traditionally used to describe the Navajo verb, other analyses have been proposed by Athabascanists.
Pronominal inflection
Navajo verbs have pronominal (i.e. pronoun) prefixes that mark both subjects and objects. The prefixes can vary in certain modes, particularly the perfective mode (See Mode and Aspect section below for a discussion of modes). The prefixes are inflected according to person and number. The basic subject prefixes (and their abbreviations as used by Young & Morgan) are listed in the table below: