Kho'ini (alternatives: Xoini, Xo'ini, Khoeini, or Di) is a Tatic dialect or language spoken in northwestern Iran, and is one of many Western Iranian languages. It is spoken in the village of Xoin and surrounding areas, about 60 kilometres (37 mi) southwest of Zanjan city in northern Iran. The Xoini verbal system follows the general pattern found in other Tati dialects. However, the dialect has its own special characteristics such as continuous present which is formed by the past stem, a preverb shift, and the use of connective sounds. The dialect is in danger of extinction.

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Kho'in (Persian: خوئین), also spelled as Xo'in an Khoein, is located in "Ejarud" rural district of Zanjan Province at the end of a long valley. In recent decades the village has lost its centrality because of veering the road of Zanjan to Bijar from Xoin. In 1960, the farmers was growing fruits around on the slopes of the hills, but Xoin's Qanats were neglected; many of the houses deteriorated already and a number of inhabitants had been migrating to Tehran seeking works. The population was 800 to 900 at the time and declining.

There has been a sense of nostalgia about the better days of Xo'in among the dwellers. Local beliefs hold that in the Qajar period some Xoinis emigrated to Merv, Ashgabat and Baku. There is a cavernous dent called "Dei-manda", meaning, "remnant of a fort" (known in other parts of Iran as "Qaleh Gabri/Gowri"), said to have been made by Zoroastrians. Some villagers legendarily believed that Xoinis had earlier been Gowr. They gave credence to being originally from Sistan. Some said when Bahman invaded Sistan to avenge his father, Esfandiyar, the descendants of Rostam fled and came to Xoin. In spite of dwindling estate, the village has 8 maintained mosques and a Tekyeh.

Azeri Turkic has mostly replaced Xoini, however in the 1960s, the extent of the dialect was as follows:

• Sipkamar (Persian: "Sefidkamar"): It is a village to the west of Xoin. The dialect was best preserved there. It had some 70 households in 1963. Sefidkamar has been more flourishing than Xoin. The access road is rather doubly arduous and limits communications, which may have been instrumental in the dialect's survival.
• Xoin: Azerbaijani language is the predominant language and the indigenous dialect was fading away in 1960 and might be extinct by now. In Aruz Mâla, the northern quarter of Xoin, the dialect is somewhat better known than in Aš Mâla, the southern quarter, where almost no one knows the language any longer.
• Sa'idabad: In its lower quarter, they speak mostly the dialect.
• Garneh: A couple of kilometers from Xoin. The people speak the dialect.
• Sura: A village to the east of Xoin, which had some 250 inhabitants. Some knew the dialect.
• Balubin (Persian: "Balbavin"): The dialect is spoken side by side with Turkic.
• Halab: The language had practically disappeared, being replaced by Azerbaijani. Just one old man could remember a few sentences in 1960.

Some sounds are approximate. Some of the vowels like "e, â, o, u" and "i" show variations.

The consonants are: p, b, t, d, č, j, k, g, x, xʷ, q, f, m, n, r, l, s, z, ž, š, h, v, w, y.

In Xoini, vowel harmony, gemination and lengthening more or less occurs.

Prepositions, postpositions and the conjunction "and" of Xoini are as follows:

Xoini has been impacted by Turkic Azeri to some extent. That includes borrowing a number of verbal forms, for example: -miš which is attached to the past stem of some verbs to form a verbal noun, e.g., ^wut-miš (saying). The postposition, -da (from) seems to be Turkic. There exist also a number words e.g.: düz (straight, right).