Several names have been in use for this family. The most common term, Northeast Caucasian, contrasts the three established families of the Caucasus language area: Northeast Caucasian, Northwest Caucasian (Abkhaz–Adyghean), and South Caucasian (Kartvelian). This may be shortened to East Caucasian. The term Nakh(o)-Dagestanian can be taken to reflect a primary division of the family into Nakh and Dagestanian branches, a view which is no longer widely accepted, or Dagestanian can subsume the entire family. The rare term North Caspian (as in bordering the Caspian Sea) is only used in opposition to the use of North Pontic (as in bordering the Black Sea) for the Northwest Caucasian languages.
Historically, Northeast Caucasian phonemic inventories were thought to be significantly smaller than those of the neighboring Northwest Caucasian family. However, more recent research has revealed that many Northeast Caucasian languages are much more phoneme-rich than previously believed, with some languages containing as many as 70 consonants.
In addition to numerous oral obstruents, many Northeast Caucasian languages also possess a number of back consonants, including uvulars, pharyngeals, and glottal stops and fricatives. Northeast Caucasian phonology is also notable for its use of numerous secondary articulations as contrastive features. Whereas English consonant classes are divided into voiced and voiceless phonemes, Northeast Caucasian languages are known to contrast phones into voiced, voiceless, ejective, and tense variants, which contributes to their large phonemic inventories. Some languages also include palatalization and labialization as contrastive features. Most languages in this family contrast tense and weak consonants. Tense consonants are characterized by the intensiveness of articulation, which naturally leads to a lengthening of these consonants.
In contrast to the generally large consonant inventories of Northeast Caucasian languages, most languages in the family have relatively few vowels. However, there are some exceptions to this trend, such as Chechen, which has at least twenty-eight vowels, diphthongs, and triphthongs.
Percentage of Northeast Caucasian languages by speakers