Matsés, also referred to as Mayoruna in Brazil, is an indigenous language utilized by the Matsés, inhabitants of the border regions of Brazil and Peru. Matsés communities are located along the Javari River basin of the Amazon, which forms part of the border between Brazil and Peru; hence the term river people. This term, previously used by Jesuits to refer to inhabitants of that area, is not formally a word in the Matsés language. The language is vigorous and is spoken by all age groups in the Matsés communities. Several other indigenous are also spoken in Matsés communities by women captured from neighboring tribes and some mixture of the languages occur. Dialects are Peruvian Matsés, Brazilian Matsés, and the extinct Paud Usunkid.

Etymology A term with Quechua origins, Mayoruna translates to = river; = people. Colonizers and missionaries during the 17th century used this term to refer to the Indigenous peoples that occupied the lower Ucayali Region, Upper Solimões and the Vale do Javari.

Speakers From research gathered in 2003, Fleck states that the Matsés language is spoken by approximately 2,000-2,200 Matsés, since being contacted in 1969. In Brazil, the Matsés inhabit the Vale do Javari Indigenous Territory (IT) that covers 8,519,800 hectares of land. The land is distributed among eight communities that are mostly located within the IT borders. According to a more recent census (2007), the population of Matsés in Brazil was 1,143 people. Meanwhile, in 1998, the Peruvian Matsés population reached a total of 1,314 people.

It is very common for Matsés families in the northern Pano group to shift between villages, including across national borders. As a result, it becomes difficult to establish trustworthy data for the Matsés populations in Brazil and Peru. Currently, Matsés in Brazil identify themselves as monolingual, since most children in Matsés communities are nurtured and taught exclusively in the Matsés language. For this reason, the level of endangerment of the language is relatively low. The Instituto Socioambiental states: "Only those people who have worked or studied in the surrounding Peruvian or Brazilian towns speak Portuguese or Spanish fluently." This strongly indicates that the language will sustain itself throughout generations. One of the most important functions of language is to produce a social reality that is reflective of that language's culture. When children are raised learning the language, the continuation of the cultural traditions, values, and beliefs is enabled, reducing the chances of that language becoming endangered.

Classification Currently, the Matsés language belongs to one of the largest subsets within the Northern Pano region. The Panoan family of languages is known to be spoken in Peru, western Brazil, and Bolivia. In turn, Panoan languages are included within the larger Pano-Tacanan family.  This language group includes languages of Indigenous groups similar to the Matsés, including Matis, Kulina-Pano, Maya, Korubo, and other groups that presently evade contact with the outside world (De Almeida Matos, 2003). Not only are these Indigenous groups culturally similar, they share mutually intelligible languages.

Literature Bibliographies about Panoan and Matsés linguistic and anthropological sources can be found in Fabre (1998), Erikson (2000), and Erikson et el. (1994). A Pano-Takana bibliography written by Chavarría Mendoza in 1983 is outdated, but still has relevant information about some linguistic and anthropological works on the Matsés. Missionaries from the Summer Institute of Linguistics (SIL) produced the first descriptions of the Matsés language. Researchers utilized escaped captives as consultants and were able to study the language and culture from the verbal affirmations of captives before they were able to make contact in 1969.

The most extensive published grammatical description of this language is the educational work done by the SIL, intended to teach the Matsés language to Spanish speakers. This work focused on the morphology of the language as well as the phonology and syntax systems. Literature which includes phonological descriptions, grammatical descriptions, collections of texts and word lists can be found in the work published by Fields and Kneeland during (approximately) 1966 to 1981. Kneeland (1979) has developed an extensive modern lexicon for Matsés which includes approximately an 800-word Matsés-Spanish glossary, along with some sample sentences. Work completed by Wise (1973) contains a Spanish-Matsés  word list with approximately 150 entries.

Carmen Teresa Dorigo de Carvalho, a Brazilian fieldworker and linguist, has been conducting linguistic analyses based on her work about the Brazilian Matsés. Her contributions to the study of this language include her Master's thesis on Matsés sentence structure and a PhD dissertation on Matsés phonology, based on an optimality theory treatment of Matsés syllable structure and many other aspects of Matsés phonology. In addition to this work, she published an article about Matsés tense and aspect, an article on split ergativity, and an unpublished paper on negation in Matsés and Marubo.

Phonology Matsés has 21 distinctive segments: 15 consonants and 6 vowels. Along with these vowels and consonants, contrastive stress also is a part of the phoneme inventory. The following charts contain the consonants and vowels of the language, as well as their major allophones that are indicated in parentheses.

Vowels The vowel system of Matsés is peculiar in that no vowels are rounded. Both of its back vowels should accurately be represented as and but the convention is to transcribe them orthographically with and .

+ VowelsFrontCentralBackClose Mid Open

Consonants + ConsonantsLabialAlveolarRetroflexPalatalVelarGlottal Nasal () Plosive     () Fricative Affricates Approximant Flap

Morphology The Indigenous Brazilian language, Matsés is a language that falls into the classification of both an isolating and a polysynthetic language. Typically, single-morpheme words are common, and some longer words could include about 10 morphemes. Still, the general use of morphemes per word in the language tends to be 3 or 4. Half of the Matsés language makes use of simple morphemes, while "verbal inflectional suffixes, transitivity agreement enclitics, and class-changing suffixes are, with very few exceptions, portmanteau morphemes." Morphemes normally, imply a one-to-one association between the two domains, but the Matsés language permits portmanteau morphemes to be part of the morphology. The distinction applies to morphemes, as productive synchronically segmented forms, while a formative morpheme includes "historical forms that are fossilized sub-morphemic elements with form-meaning associations." Root words in the language possess lexical meaning and need to occupy the nuclear parts of the word. What helps identify the nuclear word, is that it involves the use of free morphemes within the phrase, also if it occurs alone without other phonologically attached material. Free and bound morphemes also distinguish roots from affixes/clitics. Roots are morphemes that can also occur with inflectional morphology. However, some adverbs must be inflected for a transitivity agreement, as well as verbs that are not being used in the imperative mode, or that occur alone as monomorphemic words, because semantically monomorphemic words are incompatible with the imperative mode. All roots in the language can occur with no phonologically attached material, or with inflectional morphology. A stem is combined with either a root with one, none, or multiple affixes/clitics. Words are defined as a stem that is combined with inflectional suffixes, when it is necessary to do so.

A pronoun is a word used as a substitute for a noun, it may function alone, or as a noun phrase to refer either to the participants in the discourse or to something mentioned in the discourse. Typically, in Matsés, pronouns are divided into four types: personal, interrogative, indefinite, and demonstrative. Each of these types of pronouns include three case-specific forms, that are known as absolutive, ergative/instrumental and genitive. Pronouns in this language are not distinguished by number, gender, social status or personal relations between the participants in the discourse.

Inflection vs Derivation Inflection is the change in the form of a word, usually by adding a suffix to the ending, which would mark distinctions such as tense, number, gender, mood, person, voice and case. Whereas derivation is a formation of a new word or injectable stem that comes from another word or stem. This usually occurs by adding an affix to the word, which would make the new word have a different word class from the original. In Matsés, inflection normally only occurs on verbs as a lexical-class-wide and syntactic-position-wide phenomenon. There are a set of suffixes that include finite inflection and class-changing suffixes that must occur on finite verbs. Adjectives are also a word class that have a lexical-class-wide inflection. Adverbs and postpositions have a marginal inflectional category known as transitivity agreement.

Traditionally, derivational morphology includes meaning-changing, valence-changing and class-changing morphology. In the reading A Grammar of Matsés by David Fleck, he uses the term "derivational" to refer to only meaning-changing and valence-changing morphology. This is due to the fact that class-changing morphology patterns are closely related to inflectional suffixes. For the verbs in Matsés, the inflectional suffixes and class-changing suffixes are in pragmatic contrast, (shown in example 1), so it could be concluded that all verbs in this language either require class-changing morphology or inflection.

Table 2 displays the differences between derivational and inflectional/class-changing morphology in the language Matsés.

+ Table 2Derivational MorphologyInflectional/Class-changing morphology Optional Closer to root Simple morphemes Most lexical classes have them Obligatory (at least in some situations) Further from root Almost all are portmanteau morphemes Most are restricted to verbs

Reduplication There was a generalization put forth by Payne (1990), stating that in lowland South American languages, all cases of reduplication are iconic. This means that they are indicating imperfective action, greater intensity, progressive aspect, iterative, plurality, or onomatopoeia of repeated sounds. Matsés, does not confirm this generalization, as there are various different meanings that have to do with reduplication, which includes iconic, non-iconic, and "counter-iconic" reduplication. A summary of the different functions and meanings of reduplication in Matsés are shown in Table 3.

+ Table 3Iconic Suffixed verb reduplication = distributive (iterative, plural, habitual, spatial, distribution) Adverb reduplication = distributive Cliticized postposition reduplication = distributive Some animal names mimic animal call with repetitive notesNon-iconic Noun reduplication = adjectivization "Counter-iconic" Unsuffixed verb reduplication = incompletely, improperly, hurriedly Unprefixed adjective reduplication = de-intensification (i.e., 'somewhat X') Prefixed adjective reduplication = partly (i.e., adjective only applies to part of the prefixed body part) Uncliticized postposition reduplication: de-intensification

Syntax

Case and Agreement