It is very closely related to the Unami Delaware, but the two are sufficiently different that they are considered separate languages.

[6][3] As of 2018, Munsee was spoken only on the Moraviantown Reserve in Ontario, Canada, by two elderly individuals, aged 77 and 90,[7][8][9] making it critically endangered.

Munsee and Unami constitute the Delaware languages, comprising a subgroup within Eastern Algonquian.

manan, manhan; form suggests 'small island'); cognates in other Algonquian languages are e.g. Ojibwe minis, 'island'.

[19] Orthographic ⟨ink⟩ in the form Minisink is the modern Munsee locative suffix /-ənk/ (discussed below in the Grammar section).

[20] Kraft's claim that Munsee is not an indigenous term, and that it results from a "corruption" of English use of Minisink is incorrect.

[27] The English term Lenape is of Unami origin,[30] and is used in English as a self-designation by speakers of Unami;[18][31][32] Exceptionally among scholars, Kraft uses Lenape as an English-language cover term to refer to all Delaware-speaking groups, while noting that this usage is "not entirely appropriate".

The arrival of European explorers, traders and settlers resulted in the progressive displacement of Munsee people over a period of several centuries.

Munsee groups affected by this process ultimately moved away from their homeland to communities in both the United States and Canada.

Since the early 21st century, the language has been taught to tribal members of the Stockbridge-Munsee Band of Mohican Native Americans, and the Delaware Nation, Moraviantown Reserve.

)[36][37] Aboriginally, and for a period subsequent to the arrival of Europeans, Munsee was spoken within a series of small and largely autonomous local bands, located primarily within the drainage of the Hudson and upper Delaware rivers, the major river systems of the area.

[6] These groups spoke localized varieties of the language now called Munsee, but there is little information on dialect variation within the Munsee-speaking area.

Metrical rules of syllable weight assignment play a key role in the assignment of word-level stress, and also determine the form of rules of vowel syncope that produce complex but mostly regular alternations in the forms of words.

[43] Munsee has the following inventory of consonants; International Phonetic Alphabet (IPA) values are given in brackets.

Short /a/ has values centring on [ʌ], with [a] occurring before [hC] (where 'C' represents any stop or the lateral consonant).

[45] Syllable weight plays a significant role in Munsee phonology, determining stress placement and the deletion of certain short vowels.

(a) ăsə́n 'stone' (disyllabic Weak-Strong) The grammar of Munsee is characterized by complex inflectional and derivational morphology.

Inflection in Munsee is realized through the use of prefixes and suffixes added to word stems to indicate grammatical information, including number (singular or plural), gender, person, possession, negation, obviation, and others.

Linguists have tended to use common phonetic transcription symbols of the type found in the International Phonetic Alphabet or similar Americanist symbols in order to represent sounds that are not consistently represented in conventional standard writing systems.

[48][49] A practical orthography for Munsee has been created in the context of various language preservation and documentation projects.

Similarly, the breve accent is used to indicate an ultra-short [ə] that typically occurs before a single voiced consonant followed by a vowel.

[54] However, as of April 2022, only one fluent speaker of Munsee remained, an elderly woman named Dianne Snake.

[54] A large class of particles and pre-words that are usually heard with final /-ɘ/ retained the original /-i/ in the speech of some speakers.

[54] Another large class of particles and pre-words are found in older sources ending in /-Í·wi/, e.g.[55] Some words have variation between underlying | a | and | ə |.

[55] It is possible to determine which vowel is older and which might be the innovation by using evidence from other Algonquin languages, other Munsee communities and earlier sources.

Some usages can be traced directly to the Northern Unami language that was earlier spoken by some members of the Munsee community.

In comparison, Unami has undergone extensive phonological innovation, coupled with morphological regularization.