Máku ['mako]^[1], also spelled Mako (Spanish Macú),^[1] and in the language itself Jukude, is an unclassified language and likely language isolate once spoken on the Brazil–Venezuela border in Roraima along the upper Uraricoera and lower Auari rivers, west of Boa Vista, by the Jukudeitse^{[clarification needed]}. 300 years ago, the Jukude territory was between the Padamo and Cunucunuma rivers to the southwest.

The last speaker, Sinfrônio Magalhães, died in 2000. There are currently no speakers or rememberers of Máku and no-one identifies as Jukude any longer. Aryon Rodrigues and Ernesto Migliazza, as well as Iraguacema Lima Maciel, worked on the language, and the data was collected into a grammar by Chris Rogers published in 2020.^[1]

The people called themselves jukude-itse [zokudeitse]^[1]: 3 (person-PL) 'people'. When speaking to outsiders, they referred to themselves as [ˈmaku] or [ˈmako]. Maku ~ Mako (in Spanish orthography Macu or Maco) is an Arawakan term for unintelligible languages and people held in servitude in the Orinoco region. (See Maku people for a partial list.) While the stress of the word in other languages called 'Maku' may be on either the first or final syllable, as Máku/Mácu or Makú/Macú (Migliazza, Fabré), the word was pronounced with initial stress by the jukudeitse and so the name is often written with stress on the first syllable: Máku (Dixon & Aikhenvald (1999), Maciel (1991), and Rogers (2020)) or Máko (Campbell 2012),^[2] though also Makú or simply Maku (Migliazza). The disambiguator Maku-Auari has also been used.^[3]

Suggested genetic relations involving Máku include:

• with Arawakan
• with Warao
• within a Kalianan grouping with Arutani–Sape (a.k.a. Makú)
• within a Macro-Puinavean grouping with Nadahup (a.k.a. Makú), Katukinan, and Arutani–Sape

Kaufman (1990) finds the Kalianan proposal "promising", though he is now dated.

Jolkesky (2016) notes that there are lexical similarities with the Sape, Arutani, and Warao languages, as well as the Saliba-Hodi, Tikuna-Yuri, Katukina-Katawixi, and Arawa language families due to contact.^[4]

The Máku syllable structure is (C)(C)V(V)(C).^[1]: 36

/k/ is voiced to [g] intervocalically and can occasionally be realized as [g] in other environments too.

/j/ is sometimes realized as [ʑ] word-initially before /a u/ or word-medially, as in /jukude/ [ʑokude̞] 'person'. It can occasionally be fronted to [ð] or [z].

Nasals assimilate to the place of articulation of the stop they precede.

/w/ is realized as [ʋ] before /i e/. It is realized as [ʋ] or [ɥ] before /y/ (a sequence which only occurs in the word /lymywy/ 'take'). Rogers (2020) does not state that /w/ is realized as [ʋ] before /ɨ/, but provides the example /wɨtsɨ/ [ʋɨtsɨ] 'mouth'.

/d/ is realized as laminal before [u] – in some words this is in free variation with [d].

/s, ts, n, k/ are palatalized to [ʃ, tʃ, ɲ, c] before /i, y/, while /t, d, l/ become [tʲ, dʲ, lʲ].^[1]: 20-26

Although there exist minimal pairs between /o/ and /u/, some words show free variation between /u/ and /o/, and [o] is an allophone of /u/ in some environments. Rogers (2020) hypothesizes that these patterns are a result of a diachronic sound change in progress and that /o u/ do not represent separate phonemes synchronically.

Apart from the sequences [eo], [au~ao] and [ia], as well as /ai oi/ [aj oj] within a word stem, vowel-vowel sequences are resolved by deleting the first vowel of the sequence, e.g. /teana/ [tana] 'I smell (it)'. The first vowel in a stem may also be deleted in fast speech.

/a/ and /e/ are realized as [ə] when unstressed.

High and mid vowels are lowered word-finally.

Vowels are nasalized following a nasal consonant, /ʔ/ or /h/.^[1]: 32-35

Máku nouns and verbs inflect for person - either the person of the possessor, on nouns, expressed by a prefix, or of the subject and object, on verbs, which may be prefixes, infixes or suffixes, depending on the verb. There are also suffixes which express plurality of a possessor or subject. The language marks clusivity by distinguishing first person singular from first + second person (inclusive), first + third person (exclusive) and first + second + third person ('unified'). Nouns also inflect for number and case via suffixes. Verbs also inflect for tense, aspect, mood, evidentiality and negation via suffixes.

Noun phrases exhibit the word order possessor possessor-possessed, or noun-modifier. Demonstratives and numerals typically occur before the nouns they modify. There are postpositions which follow nouns.

Intransitive clause word order is typically subject-verb, and transitive clause word order is most commonly SOV. Indirect objects are typically placed after the verb. Phrases which represent new, focused referents may be fronted to the start of a clause or sentence. Any phrase in focus, both nominal and verbal, can take the focus enclitic =ke.

Máku has motion-complement serial verb constructions, with subject-verbal complement-motion verb order.

Coordination is accomplished via juxtaposition, at the phrase and clause levels.^{[1]: 98-127}

Loukotka (1968) lists the following basic vocabulary items for Máku.^[5]