Yatzachi Zapotec is an Oto-Manguean language of the Zapotecan branch, spoken in northern central Oaxaca, Mexico. 2,500 self-reported being Yatzachi speakers for the 1990 Mexican census, but the actual number of speakers is unknown. The Yatzachi dialect belongs to the Villa Alta group of Zapotec dialects, of which the main dialect is San Bartolomé Zoogocho. The degree of mutual intelligibility between Yatzachi and the San Bartolomé Zoogocho dialect is estimated to be around 90 percent.

Yatzachi Zapotec has six vowels. The a, e, and i are the same as these vowels in Spanish. In earlier forms of Zapotec, there was a sound between o and u, which in the case of Yatzachi Zapotec was closer to the o sound, but in other Zapotec dialects was more of a u sound. In the modern Yatzachi dialect, both the o and the u sound exist, although the u is only found in Spanish loanwords.

In addition, Yatzachi Zapotec has a schwa sound. This sound is more neutral and has a tendency to adapt to the adjacent sounds and is not used in stressed syllables. It is often difficult to distinguish between the schwa and e sound, however minimal pairs exist such as in zide´ "wine" and zidə´ "sticky," making a distinction between the two sounds necessary.

In Yatzachi Zapotec, it is easier to think of consonants as having a distinction between fortis and lenis rather than voiced and voiceless. Fortis describes sounds that require a greater effort to articulate, while lenis describes sounds that require lesser effort. Voiced sounds are lenis, and sounds that are either voiceless or aspirated are considered fortis.

A distinction between aspirated and non-aspirated sounds occurs on the consonants ch, x, l, and n. Yatzachi Zapotec also contains many Spanish loanwords, and thus borrows letters from Spanish orthography to write these sounds, such as ñ and ll [ʎ]. The digraph rr (also borrowed from Spanish) is used when the trilled r occurs medially in a word, however a single r is used to represent the trill at the beginning or end of a word. Elsewhere, a single r represents a tap consonant. Zapotec also features rounded or labialized consonants which are written as digraphs with the consonant followed by a w such as jw, gw, and cw. The places of articulation are identical to j, g, and c, respectively. Occasionally the w is replaced by u which is more in accordance with Spanish orthography in which w does not normally exist. The saltillo, or glottal stop, is found after vowels or the sound n and counts as a distinct phoneme, as illustrated with the minimal pairs ga "new," and ga´ "green."

In the table below, the bold letters represent the way the sound is written according to Yatzachi Zapotec orthography, and the symbols in brackets reflect the sound as written in the International Phonetic Alphabet.

The Villa Alta Zapotec dialects have three tones: high /¹/, mid /²/, and low /³/. The differences in these tones can be identified with the use of contrastive sets. The idea of contrastive sets is similar to the use of minimal pairs to identify phonemes. For example, de³za¹n ya¹ "a lot of bamboo" versus de³za¹n ya² "many steam baths". In this case, the difference between the high and mid tones is shown in the last syllable.

Most Zapotec nouns do not vary morphologically in gender or number. There are two ways to tell whether a given noun is plural; (1) the noun is accompanied by a quantifier such as a number, or (2) if a noun is the subject of a sentence, then the verb of the sentence will be in the plural form.