The vowel becomes the labial semivowel in several environments: in postnuclear position, before another vowel, and at the beginning of the word or syllable. The semivowel is devoiced if the tone rises and the following vowel is,,. The vowel becomes the palatal semivowel in postnuclear position. Nasalization in Nukak language is a prosodic property of the morpheme that affects all segments within each morpheme except voiceless stops. Each morpheme is either completely nasal or completely oral.
Consonants
There are eleven consonant phonemes: ; ; ; ; ; ; ; ; ; ; . The following table of consonant phonemes shows each phoneme followed by the corresponding letter in the Nukak alphabet, where different.
is pronounced when followed by and when preceded by a voiced consonant. If is preceded by or, it is pronounced voiceless. With some infixes or prefixes, is replaced by when it is followed by any vowel or or in nasal suffixes. The voiced palatal allophones ~ can be considered variants of the vowel when they precede a vowel in the initial position of a root or of an affix, or when they lie between two vowels.
Tones
The nuclear vowels of nouns, verbs, and adjectives bear tone. Nukak has two tonemes : high and rising. In the surface phonology there are also a low tone and a falling tone. The rising and falling tones are accompanied by lengthening of the vowel, however, the falling tone has been analyzed as actually being the allomorph of the high tone in closed syllables ending in or an occlusive consonant, except orin morpheme final open syllables. Unaccented syllables always bear the low tone. The high and rising tones occur only in monosyllabic, monomorphemic lexemes. Multisyllabic morphemes are stressed on the first syllable.
The Nukak nouns are marked for gender, number, and case. There are two grammatical genders. The plural of animate nouns is indicated with the suffix -wɨn. Case markers include the following: Depending on the nounlexeme, the vocative case is expressed by a tone change; by the suffix -a; or by duplicating the nuclear vowel after the root final consonant. Nouns can take tense suffixes, e.g., -hîpî' , "that which came before", and a question suffix, -má' . The connective formative -tɨ expresses either coordination with another noun, i.e., "also", or the clause conjunction, "and". Noun classifying suffixes are common: -na' , -da' "small and round", -dub "small, slender, and pointed", -nɨi "flat and thin", -ne "long-haired", -yi "abundant, profuse".
Pronouns
Possessive pronouns are free forms: wî' "mine", mí' "yours singular", aî' "his", mi'î' "hers", wîi' "our", ñí' "yours plural, i'î' "theirs". The relations "my, your, her", etc. are expressed with prefixes on the possessed noun: wa "my", ma "your singular", a, "his", mi "her", hi "our", ñi "your plural", i "their". In conjugation, the same prefixes are agent markers. They occur either with or without personal pronouns.
Interrogative words
déi, de pán "what?" referring to actions, háu'ka, de'e "who?", déimɨnɨ "when?", ded "where?", jáu' why?". They combine with various other markers, e.g., case suffixes: the allativede' yúkú "towards where?", the instrumentalde'e hin "with whom?", the genitive de'e î' "whose?". Interrogatives combine with tense markers as in jáu' ra' .
Verbs
Verbs are conjugated with a subject prefix and with suffixes and infixes expressing aspect ; tense and mood. For example: The imperative mood is formed by duplicating the last vowel of the verb stem, after the root final consonant or semivowel. The vowels and are pronounced as semivowels , when duplicated after the final consonant. The past imperfect is formed by suffixing to the stem the duplicate of the last vowel in the stem plus : . The combination of the past imperfect suffix with the marker -tí´ marks a past subjunctive: jɨm "to be"; jɨmɨ "may have been",; past imperfect jɨmɨp "was"; subjunctive preterite jɨmɨptí´ "if it were". Verbal negation is expressed in different ways: with the suffix -ka, which comes between the verb root and the tense, mood, and aspect markers; with certain prefixes to the verb stem; with the words yab´ , "no", dɨi´ , "refuse", îí´ , "without effect". Negative commands have a specific marker, -kê´ . There are many compound verbs. The elements may be two or more verb roots or they may be a verb root plus a noun, adjective, or adverb. The marker -a converts an intransitive verb root into a transitive verb. Verbs are nominalized with the suffixes -hát, the abstract idea of the action, -pe' , the affected object, participle. The agent of the action is indicated with the agentive prefix and a suffix expressing person and number. The agentive suffixes are -ni' for the first person, second person, and third person singular feminine; -ni for the third person singular masculine; and -nit for the third person plural. To these may be added the marker for imminence, currently in progress, or emphasis, -yé' . All verb roots end in a consonant or semivowel. The meaning "to be" can be expressed in two ways: explicitly with the verb jɨm or tacitly through the various interrogative markers along with the personal pronouns, and occasionally with another verb, yit, which has the emphatic form yittí' , "I am".
Adverbs
The Nukak language has many adverb forms. Various adverbs are important in the construction of sentences. For example, they frequently use hébáká "indeed", and for even greater insistence, -yé' is suffixed. The verbal link tɨtíma'hî "after" can occur between the subject and the object and verb. Morphologically, some adverbs are independent words; these can follow nouns, like hattí' "also", "neither", "yet". There are some adverbial suffixes, e.g., -hê' '' "only", "precisely".
Interjections
Kútu' "Hey!", "Attention!" is an exclamation said in order to begin to speak. Other exclamatory words or phrases are hâré "Be careful!" or dɨpí hâré "Be very careful!"; waá'yé' "Enough!; be'bét yé' "Hurry up!"; ni'kábá'í' "That's it!".
