Consonants

The consonant /d/ (as in jaduj 'short', krwỳdy 'beak') is exceedingly rare; /t͡ʃ/ (as in xãn 'cat', jaxwe 'naughtly') is rare in the onset position. The consonant /ɾ/ in the coda position is always followed by an epenthetic echo vowel, which may be an exact copy of the preceding vowel or [i] (if the preceding vowel is /a/ or sometimes /ɔ ʌ/). That way, the words /paɾ/ 'his/her foot' and /puɾ/ 'garden' are pronounced [ˈpaɾi], [ˈpuɾu] (and written pari, puru).

Vowels

The vowels /ã/ (as in mrã 'to walk', xãn 'cat') and /ũ/ (as in tũm 'old') are rare and mostly go back to earlier oral vowels /a/ and /u/ in certain environments. The vowel /ɯ̃/ (as in nhỹ 'to sit') is also somewhat rare.

In some analyses, Mẽbêngôkre has five diphthongs which occur word-finally only: uwa /uᵊ/, ija /iᵊ/, eje /ɛᵊ/, ôwa /oᵊ/, ĩja /ĩᵊ/. These are realized phonetically as [ˈuwa], [ˈija], [ˈɛjɛ], [ˈowa], [ˈĩj̃ã].^[5]: 69 Other authors analyze them as monophthongs followed by a glide (/w/ or /j/) in the coda position, which is followed by an epenthetic echo vowel. Some examples follow.

Syllable structure

The maximal syllable structure of Mẽbêngôkre is /CCCVC/. Any consonant may occur as a simple onset. Complex onsets may by formed by a combination of one of /p b m k ŋ/ and one of /ɾ j/ (pr-, br-, mr-, kr-, ngr-, pj-, mj-, bj-, kj-, ngj-); /t n ɾ t͡ʃ d͡ʒ ɲ k ŋ kɾ ŋɾ/ can also combine with /w/ (tw-, nw-, rw-, xw-, djw-, nhw-, kw-, ngw-, krw-, ngrw-). The coda may be any of /p t t͡ʃ k m n ɲ ɾ j/ (in analyses which do not recognize the existence of diphthongs, also /w/).

Finiteness morphology

As in all other Northern Jê languages, Mẽbêngôkre verbs inflect for finiteness and thus have a basic opposition between a finite form and a nonfinite form. Finite forms are used in matrix clauses only, whereas nonfinite forms are used in all types of subordinate clauses as well as in some matrix clauses (with a particular aspectual interpretation). The morphology associated with the finite/nonfinite distinction includes suffixation and/or prefix substitution.^[9] Some verbs lack an overt finiteness distinction.

The following nonfinite suffixes occur in the language: -rV (the most common option, found in many transitive and intransitive verbs) and its allomorph -n (following front nasal vowels), -nh (found chiefly in transitive verbs), as well as -k, -m, and -x (found in a handful of intransitive verbs).

In a handful of verbs, all of which end in an underlying stop, the nonfinite form does not receive any overt suffixes, but it is nevertheless distinct from the finite form because the latter lenites the stem-final consonant (-t, -k → -rV, -rV).^[11]: 544

Person inflection and case

In Mẽbêngôkre, postpositions, and relational nouns inflect for person of their internal argument by taking absolutive or accusative person prefixes. The accusative series is required by a subclass of transitive verbs (in finite clauses only) as well as by some postpositions; the absolutive series is the default one and is found with most transitive and all intransitive verbs in finite clauses, with all verbs in nonfinite clauses, with all relational nouns, and with some postpositions. External arguments of verbs are not indexed by person prefixes but are rather encoded by nominative (unmarked) noun phrases (including personal pronouns) in finite clauses, or by ergative phrases in nonfinite clauses. In nouns, nominative, absolutive and accusative are unmarked, whereas the ergative case is marked by the ergative postposition te.

The person prefixes which index the internal argument of verbs, postpositions, and nouns are as follows.^[12]: 41

The nominative and ergative forms of the pronouns are as follows.^{[12]: 40–1}

The pronouns have also an emphatic form, which is used when a pronoun is focalized and can also be considered a grammatical case on its own.

Voice

In Mẽbêngôkre, transitive verbs may be detransitivized by means of an anticausative or an antipassive derivation. The anticausative marker is the prefix a(j)- in the finite form and the prefix bi- in the nonfinite form of the verb. The antipassive derivation is achieved by means of the prefix a- in the finite form and the prefix djà- or dju- in the nonfinite form of the verb.^[13]

Derivational morphology

Reduplication

Reduplication may be used to convey repeated action and possibly transitivity, as in the following examples:^[13]

In some verbs, such as prõrprõt ‘to float up and down’, the final consonant of the reduplicated base changes from a stop /t/ to a rhotic /ɾ/.

Morphosyntactic alignment

Prototypically, finite matrix clauses in Mẽbêngôkre have a nominative–accusative alignment pattern, whereby the agents of transitive verbs (A) and the sole arguments of intransitive verbs (S) receive the nominative case, whereas the patients of transitive verbs (P) receive the absolutive or the accusative case, which has been described as an instance of a split-P alignment.^[10]: 272 There are only several dozen of transitive verbs which take an accusative patient, all of which are monosyllabic^{[14]: 30–2} and have distinct finite and nonfinite forms. It has been suggested that all transitive verbs which satisfy both conditions (monosyllabicity and a formal finiteness distinction), and only them, select for accusative patients,^[11]: 538 while all remaining transitive verbs take absolutive patients in Mẽbêngôkre and other Northern Jê languages.

Nonfinite clauses (including all embedded clauses) are headed by nonfinite verbs and are ergatively organized: the agents of transitive verbs (A) are encoded by ergative postpositional phrases, whereas the patients of transitive verbs (P) and the sole arguments of all intransitive predicates (S) receive the absolutive case.^[14][15]

Classes of predicates

The following table summarizes the proposed classes of predicates in Mẽbêngôkre.^[15]

Instruments, locations, and prototypical agents

Mẽbêngôkre extensively uses the nouns djà ‘container’ and djwỳnh ‘owner, master’ to denote instruments (or locations) and prototypical agents, respectively, as in idjàkuru djà ‘eating utensils; eating place; food’ (literally ‘the container of my eating’) or pi’ôk jarẽnh djwỳnh ‘teacher’ (literally ‘the owner of the telling of the book’). These nouns attach to the nonfinite (nominal) forms of verbs or to other nouns, and express meanings that in other languages are frequently conveyed by special kinds of nominalizations.^[14]: 88

Tense and aspect

In Mẽbêngôkre, there is no morphological distinction between present and past, the completion or continuation of an action is determined by the narrative context. Aspectual distinctions may be conveyed by auxiliaries or by using a nonfinite form of a verb in an unembedded clause. The following sentence shows the role of verbal finiteness when determining aspect:^{[14]: 89–90}

In the semantic interpretation of the first example, the position of the event with respect to the time of the utterance can only be determined by narrative context. In contrast, the occurrence of the nonfinite form of the verb in the second example makes the event not "anaphoric to discourse, but rather coterminous with the subject's lifespan (mutatis mutandis for inanimate subjects). This interpretation has been variously described as “stative” or “subject-oriented” (in the sense that it ascribes a property to the subject, rather than focusing on the event itself) in the descriptive literature.”^[16]

Kinship terms

Mẽbêngôkre has triadic kinship terms, which express at the same time the relation of a given referent both to the speaker and the addressee.^[17]

Loanwords

Mẽbêngôkre has been in contact with the distantly related Karajá language, as evidence by a number of Karajá loanwords in Mẽbêngôkre, especially in the dialect spoken by the Xikrin group; the source of these loanwords is thought to be the Xambioá dialect. There are also loans from the Tupian languages Yudjá (Jurunan group) and Língua Geral Amazônica (Tupi-Guarani group), as well as from a hypothetical extinct Northern Jê language. More recently, lexical borrowings have been adopted from Brazilian Portuguese. Examples include:^{[18]: 13 [5]}