Tyap is a regionally important dialect cluster of Plateau languages in Nigeria's Middle Belt, named after its prestige dialect. It is also known by its Hausa exonym as Katab or Kataf.^[4][5] It is also known by the names of its dialectical varieties including Sholyio, Fantswam, Gworok, Takad, "Mabatado" (Tyap 'proper'), Tyeca̱rak and Tyuku (Tuku). In spite of being listed separately from the Tyap cluster, Jju's separation, according to Blench R.M. (2018), seems to be increasingly ethnic rather than a linguistic reality.^[6]

Native Tyap speakers are primarily found in the local government areas of Jema'a, Kaura and Zangon Kataf, although pockets of speakers are also found in Kachia and Kauru in southern Kaduna state, and Riyom (especially Takad speakers^[7]) in Plateau State of Nigeria. There are also large speaking communities in Kaduna South and Chikun Local Government Areas of the state.^[8] Skoggard (2014) presented the distribution of the Atyap (Katab) people in Nigeria to include: Niger, Nasarawa, Kaduna states and the FCT.^[9]

Meek (1931:2) suggested that the Katab (Atyap), Morwa (Asholyio), Ataka (Atakad) and Kagoro (Agworok) speak a common tongue and may be regarded as one; and later on, McKinney (1983:290) commented that the Kaje (Bajju) should likewise be included with the above, due to the linguistic and cultural similarities shared by them.^[10][11] Murdock (1959) classified Kagoro (Gworok) and other dialects comprising the current Tyap language group as "Plateau Nigerian",^[12] in his "Semi-Bantu" branch of "Bantoid subfamily" of "Negritic Stock".^[13][14] Tyap and Jju were placed by Greenberg (1963) under the "Plateau II" branch of the Benue-Congo language family. Later on, Gerhardt (1974) made a reconstruction of the branch, assigning it as "proto-Plateau". Again in 1989, Gerhardt placed Tyap and Jju under the South-Central subgroup, Central group, Plateau branch of Platoid, a division of the Benue-Congo languages.^{[5][15][16][17]} Achi (2005) stated that the Atyap speak a language in the Kwa group of the Benue-Congo language family.^[18] However, according to Bitiyong, Y. I., in Achi et al. (2019:44), the Kataf Group (an old classification) to which Tyap language belongs, is a member of the eastern Plateau. He went further to suggest that by utilizing a glotochronological time scale established for Yoruba and Edo languages and their neighbours, the separation of the Kataf Group into distinguishable dialects and dialect clusters would require thousands of years. Also mentioned was that,

Between Igala and Yoruba language, for example, at least 2,000 years were required to develop the distinction, while 6,000 years were needed for the differences observable in a comparison of Idoma and Yoruba language clusters

noting further that this indicates that

even within dialect clusters, a period of up to 2,000 years was needed to create clearly identifiable dialect separation and that it is thus a slow process of steady population growth and expansion and cultural differentiation over thousands of years.^[19]

He thereafter summarized that the implication for Tyap is that it has taken thousands of years to separate, in the same general geographical location from its about six most closely related dialects and stated that as a sub-unit, they required probably more thousands of years earlier to separate from other members of the "Kataf group" like Gyong, Hyam, Duya and Ashe (Koro) who are little intelligible to them. The stability of language and other culture traits in this region of Nigeria has been recognized.^[20][19]

The Tyap alphabet (Zwunzwuo A̱lyem Tyap ji) had 39 letters, as drafted by the Tyap Literacy Committee (TLC) during the early 1990s:^[24][25]

However, a current development as of 2018, has the Tyap Basic Alphabetical Chart reduced to 24, as follows:

The letter "ch" would henceforth be represented by the symbol "c", without the "h". All others remain the same.

Tyap has the SVO constituent order type^[33] as illustrated below in the first given example:

^[8]

^[8]

Comparing the cognate percentages between Kaje (Jju), Katab ("Mabatado" Tyap) and Kagoro (Gworok) on the Swadesh wordlist consisting of 118 items of core basic vocabulary, Wurm (1971), in his remark stated that, the cognate percentages indicate that the three ethnic groups speak dialects of the same language.^[34]

_{Percentages of cognates on the Swadesh wordlist: Wurm (1971).}

With a further comparison of their kinship terminologies, McKinney (1983:291), after comparing 174 entries between the above three found only eight to be non-cognate.^[35]

_{Percentages of kingship cognate terms: McKinney (1983:291).}

^[8] Below are comparisons made by Akau (2020) between the seven Tyap core dialects and Jju.

• 0: gum/piit/sa̱khat
• 1: a̱nyiung (also nyiung, jhyiung)
• 2: a̱feang (also feang, sweang)
• 3: a̱tat (also tat, tsat)
• 4: a̱naai (also naai, nyaai)
• 5: a̱fwuon (also fwuon, tswuon)
• 6: a̱taa
• 7: a̱natat
• 8: a̱ni̱nai (or a̱ri̱nai)
• 9: a̱kubunyiung

Some Tyap names for neighbouring and other languaɡes are as follows:

.^[8]

A research list called the "Swadesh 100-word List" presented by Shimizu (1975:414) shows that Tyap (Katab) shares the following cognate percentages with fellow Plateau languages and Jukun beginning from the highest to the lowest: 72% with Izere (Izarek), 66% with Rigwe, 50% with Chara, 49% with Berom, 42% with Tarok, 41% with Pyem, 41% with Ninzam, 39% with Kuche, 39% with Eggon, 38% with Ibunu, 37% with Rindre and 34% with Jukun.^[38]

Research has shown that the Tyap language is classified as one of the endangered languages vulnerable towards extinction.^[39]

Language is the key to the heart of a people. If we lose the key, we lose the people. A lost language is a lost tribe, a lost tribe is a lost culture, a lost culture is a lost civilization a lost civilization is invaluable knowledge lost. The whole vast archives of knowledge and experience in them will be consigned to oblivion.

— Centre for Endangered Languages (1996).

A study by Ayuba (2014) showed that Tyap is endangered and that the Hausa language and the non-transmission of Tyap by the older generation of Atyap to the younger generation largely accounted for the endangerment of Tyap.

The study recommended, among other measures, that the Atyap Community Development Association (ACDA) should set up a committee to create awareness on the need for Atyap to rise up and save their language and another to work towards establishing vacation schools where older adults would provide pre-school child care where Tyap children could be immersed in the language.^[40]

• Kuteb language