Texistepec Popoluca has been documented primarily in work by Søren Wichmann, a Danish anthropological and historical linguist and Ehren Reilly, a former graduate student at Johns Hopkins University.
However, according to a publication from the Program of Revitalization, Strengthening, and Development of the Languages of the Indigenous Nationals, in 2012 there was a recorded 238 speakers in Veracruz, Mexico (INALI).
According to early work conducted by Foster another "outstanding feature of Texistepec consonants is the strong development of voicing" especially with stops and [s].
Stress is assigned to: (1994, 469)" The vowels in Texistepec can be counted as the five listed in Table 3, for the sake of simplification and consistency as presented by multiple sources.
A few pages later we are informed that "palatalization regressively affects coronal consonants and progressively affects the high central vowel phoneme /ɨ/... TEX does not permit geminate onset consonants, and the onset is the only location where morphological rules could create the problematic /jj/" (Reilly 2002, 16).
/j-Cɨ/ → [Ci] C. /j-s/ → [ʃ] D. /j-[-COR]/ → [Cj] (Reilly 2005) "The use of a single marker... is sufficient to indicate the persons and grammatical functions...
The GFM [Grammatical function morpheme] system in TEX [Texistepec Popoluca] always uses only a single prefix on a given verb."
These patterns are clearly shown in The Complete Paradigm below which breaks down the two sets in which transitive and intransitives are marked with the Ergative/nominative split with the Absolutive in a separate grouping.
“Aspect marking occurs in the derivation process after the verb has been inflected to agree with the person a grammatical function of its arguments.
Wichmann’s research 2000 determined that “Texistepec Popoluca makes little use of adjectives, conjoined phrases, passives, participles, or subordination” (420).
Reilly mentions that “Texistepec has a class of modifiers whose status as either adjective or adverb is unclear, but which always show agreement with the subject of the clause... always uses Set A” (referring to The Complete Paradigm presented above)(2007, 1574).