Linguists in China consider the dialect spoken in Changdong, Jinxiu Yao Autonomous County, Guangxi to be the standard.

In Vietnam, Dao people belonging to the Đại Bản, Tiểu Bản, Quần Chẹt, Ô Gang, Cóc Ngáng, and Cóc Mùn subgroups speak Iu Mien dialects.

A distinguishing feature of Iu Mien consonants is the presence of voiceless nasals and laterals.

The dialect studied by Bruhn, and described in the above table, has a phoneme /ɛ/ that does not have its own spelling, but is represented in various contexts either as ⟨e⟩ or ⟨ai⟩ (which are also used for /e/ and /aɪ/, respectively).

Some other syntactic properties include the following: In the past, the lack of an alphabet caused low rates of literacy amongst the Iu Mien speakers.

It had been written with Chinese characters in China; however, this is extremely difficult for Iu Mien speakers from other countries such as Laos and from groups who now live in the West.

The alphabet is similar to the RPA used to write the Hmong language and the Hanyu Pinyin transcription scheme used for Chinese.