The Navajo language is a Na-Dene or Athapascan language. It is unique in that although the majority of the languages in the Na-Dene or Athapascan family are spoken much farther north (Alaska, Yukon, Northwest Territories, and Canadian Provinces) Navajo is spoken much farther south (in the southwest United States) by the Navajo people. Navajo claims more speakers than any other Native American language north of the Mexican border, with more than 100,000 native speakers, and this number is actually increasing with time. During World War II, Navajo was used by code talkers to send secure military messages over radio.

Linguistically, Navajo is an agglutinative language, but many of its affixes combine into barely recognisable contractions. Navajo words are altered primarily by prefixes, with circumfixes playing some part as well. The key element in Navajo is the verb, with even some noun meanings provided by verbs; many complex nouns are derived from verbs as well; for instance, the Navajo word lhéé'íí'níílh "cemetery" is actually a verb meaning "(plural objects) lie in the ground". Navajo is quite complex, with a large variety of noun classes including "animate", "round object", "long, stiff object" and "granular object". Very simple verbs in Navajo may translate into many words in English; for instance, the verb si' means "to cause a hafted object to move" or, more practically, "to practise archery".

There are four phonemic vowels in Navajo: a, e, i and o; each of these may occur long, nasalised, or with one of four tones: high, low, rising or falling. Various combinations of these features are also possible.

The consonants of Navajo are:

Bilabial       b        m  'm
Alveolar       d  t  t' n  'n
Prepalatal     g  k  k' 
  labialised      kw
Palatal                        y      'y
Postpalatal                    gh  x
  labialised                   ghw xw
Sibilant    
  alveolar                     z   s     dz  ts  ts' 
  postalveolar                 j   c     dj  tc  tc' 
Lateral                        l1  lh    dl  tl  tl' 
Glottal           '                h/x
Or, in SAMPA-style notation:
  bilabial alveolar (alveolar)
lateral		 (alveo-)
palatal		 velar labialized
velar		 glottal
stop unaspirated p t     k kw ’
aspirated   th     kh    
ejective   t’     k’    
affricate voiced2   dz dl\\ dZ      
voiceless   ts tl\\ tS      
ejective   ts’ tl\\’ tS’      
fricative voiced   z   Z G Gw  
voiceless   s l\\³ S x xw h 
liquid voiced     l j      
preglottalized       ’j      
nasal voiced m n          
preglottalized ’m ’n          
1. The lateral approximant l is treated as part of an overall lateral class in some Navajo grammars; however, it is the only approximant in the class, all other lateral phonemes being based on voiced and voiceless lateral fricatives instead. Some Athabaskan languages, notably Han, have no voiced lateral approximant, distinguishing only a voiced and voiceless lateral fricative.

2. The standard orthography uses English voiced stop symbols for the unaspirated phonemes, as in rapid speech these are frequently heard as voiced. It is also unclear from the orthography whether the affricates use a voicing or aspiration contrast.

3. Note that the first chart fails to clearly distinguish liquids and fricatives; in particular, it is unclear whether lh is a voiceless lateral liquid or a voiceless lateral fricative.

As in many northwestern American languages, Navajo is extremely poor in labial consonants.

See also