Classical Nahuatl grammar
The grammar of Classical Nahuatl is agglutinative, head-marking, and makes extensive use of compounding, noun incorporation and derivation. That is, it can add many different prefixes and suffixes to a root until very long words are formed. Very long verbal forms or nouns created through incorporation and accumulation of prefixes are common in literary works. This also means that new words can be created at will.
Orthography used in this article 
Vowel length was phonologically distinctive in this language. Long vowels are indicated with a macron above the vowel letter: <ā, ē, ī, ō>. Saltillo (glottal stop consonant, [ʔ]) is indicated with an /h/. The grammarian Horacio Carochi (1645) represented saltillo by marking diacritics on the preceding vowel: grave accent on nonfinal vowels <à, ì, è, ò> and circumflex on final vowels <â, î, ê, ô>. In the history of this language, both in its actual use and in the studies by all other colonial era grammarians other than Carochi, long vowels and the saltillo were rarely indicated. To give an adequate description of the classical Nahuatl language, it is, however, essential to mark them.
The phonological shapes of Nahuatl morphemes may be altered in particular contexts, depending on the shape of the adjacent morphemes or their position in the word.
Where a morpheme ending in a consonant is followed by a morpheme beginning in a consonant, one of the two consonants often undergoes assimilation, adopting features of the other consonant.
|ch||+||y||→||chch||E.g. oquich-(tli) "man" + -yō-(tl) "-ness" → oquichchōtl "valor"|
|l||+||tl||→||ll||E.g. cal- "house" + -tli (absolutive) → calli "house"|
|l||+||y||→||ll||E.g. cual-(li) "good" + -yō-(tl) "-ness" → cuallōtl "goodness"|
|x||+||y||→||xx||E.g. mix-(tli) "cloud" + -yoh "covered in" → mixxoh "cloudy"|
|z||+||y||→||zz||E.g. māhuiz-(tli) "fear" + -yō-(tl) "-ness" → māhuizzōtl "respect"|
Almost all doubled consonants in Nahuatl are produced by the assimilation of two different consonants from different morphemes. Doubled consonants within a single morpheme are rare, a notable example being the verb -itta "see".
The words of Nahuatl can be divided into three basic functional classes: verbs, nouns and particles. Adjectives exist, but they generally behave like nouns and there are very few adjectives that are not derived from either verbal or nominal roots. The few adverbs that can be said to exist fall into the class of particles.
The noun is inflected for two basic contrasting categories:
- possessedness: non-possessed contrasts with possessed
- number: singular contrasts with plural
Nouns belong to one of two classes: animates or inanimates. Originally the grammatical distinction between these were that inanimate nouns had no plural forms, but in most modern dialects both animate and inanimate nouns are pluralizable.
Nominal morphology is mostly suffixing. Some irregular formations exist.
Non-possessed nouns take a suffix called the absolutive. This suffix takes the form -tl after vowels (ā-tl, "water") and -tli after consonants, which assimilates to a final /l/ (tōch-tli, "rabbit", but cal-li, "house"). Some nouns have an irregular form in -in (mich-in, fish). These suffixes are dropped in most derived forms: tōch-calli, "rabbit-hole", mich-matlatl, "fishing net". Possessed nouns do not take the absolutive suffix (see Noun inflection below).
- The absolutive singular suffix has three basic forms: -tl/tli, -lin/-in, and some irregular nouns with no suffix.
- The absolutive plural suffix has three basic forms: -tin, -meh, or just a final glottal stop -h. Some plurals are formed also with reduplication of the noun's first or second syllable.
- The possessive singular suffix has two basic forms: -uh (on stems ending in a vowel) or -Ø (on stems ending in a consonant).
- The possessive plural suffix has the form -huān.
Only animate nouns can take a plural form. These include most animate living beings, but also words like tepētl ("mountain"), citlālin ("star") and some other phenomena. Plurals are formed in several ways:
- The absolutive suffix is replaced with -h (glottal stop), -tin or -meh
- Some nouns may have a reduplication of their first consonant and vowel, with the reduplicated vowel long.
|teōtl, tēteōh||tōchtli, tōtōchtin||Never occurs|
|cihuātl, cihuāh||oquichtli, oquichtin||michin, michmeh|
The plural isn't totally stable and in many cases several different forms are attested.
Noun inflection 
|Absolutive singular||cihuātl "woman"||oquichtli "man"||totōlin "turkey"||tlācatl "person (sg.)"|
|Absolutive Plural||cihuāh "women"||oquichtin "men"||totōlmeh "turkeys"||tlatlācah "persons"|
|Possessed Singular||nocihuāuh "my woman"||noquich "my man"||nototōl "my turkey"||notlācauh "my person"|
|Possessed Plural||nocihuāhuān "my women"||noquichhuān "my men"||nototōlhuān "my turkeys"||notlācahuān "my persons"|
Possessor prefixes 
|1st person singular||no-, 'my'|
|2nd person singular||mo-, 'your'|
|3rd person singular||ī-, 'his, hers, its|
|1st person plural||to-, 'our'|
|2nd person plural||anmo-, 'your'|
|3rd person plural||īn-, 'their'|
|Unknown possessor||tē-, 'their' (somebody's)|
Example: nocal, 'my house'
Some other categories can be inflected on the verb such as:
- Honorific formed with the suffix -tzin.
- cihuā-tl "woman" + tzin+ tli absolutive = cihuātzintli "woman (said with respect)"
Inalienable possession 
The suffix -yo — the same suffix as the abstract/collective -yō(tl) — may be added to a possessed noun to indicate that it is a part of its possessor, rather than just being owned by it. For example, both nonac and nonacayo (possessed forms of nacatl) mean "my meat", but nonac may refer to meat that one has to eat, while nonacayo refers to the flesh that makes up one's body. This is known as inalienable, integral or organic possession.
Derivational morphology 
- -tia derives from noun X a verb with an approximate meaning of "to provide with X " or "to become X".
- -huia derives from noun X a verb with an approximate meaning of "to use X " or "to provide with X".
- -yōtl derives from a noun X a noun with an abstract meaning of x-hood or x-ness.
- -yoh derives from a noun X a noun with a meaning of "thing full of X" or "thing with a lot of X"
The structure of verb forms 
The verb is marked with prefixes in order to agree with the person and number of the subject and the object of the sentence; additionally, verbs inflect for tense and aspect. Here are three sentence types, each containing a single word: a nominal predicate, an intransitive sentence, and a transitive sentence. Reminder: in classical Nahuatl, the spelling 'h' at the end of a syllable indicates the glottal stop, not the sound of the 'h' in 'he'.
- ticihuātl, 'you (singular) are a woman' (sentence with a noun predicate cihuātl, 'woman')
- ticochi, 'you (singular) sleep' (sentence with an intransitive verb, -cochi, 'sleep')
- ticochih, 'we sleep' (sentence with an intransitive verb, -cochi, 'sleep')
- tiquimittah 'we see them' (sentence with a transitive verb, -itta-, 'see')
Caution: ti- means 'you (singular)' but ti-____-h means 'we'.
From these examples, it can be seen that the arrangement of a verb stem and its argument affixes is as follows:
SUBJECT PREFIX + OBJECT PREFIX + VERB STEM + 'h' (example: 'ti-quim-itta-h', we - them - see - we, i.e., 'we see them')
Affixes for the arguments of the verb (subject and object) 
In the table below, Ø indicates there is no marker in the given position.
|1st person singular||ni-, 'I'||-nēch-, 'me'|
|2nd person singular||ti-, 'you'||-mitz-, 'you'|
|3rd person singular||Ø-, 'he, she, it'||-qui-, 'him, her, it'|
|1st person plural||ti (+ verb +) -h, 'we'||tēch, 'us'|
|2nd person plural||an (+ verb +) -h, 'you'||-amēch-, 'you'|
|3rd person plural||Ø- (+ verb +) -h, 'they'||-quim-, 'them'|
|Unknown||-tē-, 'somebody, something'||-tla-, 'somebody, something'|
Temporal and aspectual suffixes 
- Present: has no suffix.
- Quotidian: -:ni niquittāni "I used to see it" nipēhuāni "I used to start".
- Perfect: Optional long "o" (ō) -c/h/?/Ø (ō)niquittac "I saw him/her/it (preterit aspect)", ōnipēuh "I started"
- Future: -z niquittaz "I will see him/her/it ", nipēhuaz "I will start"
- Imperfect: -ya niquittāya "I saw him/her/it (imperfect aspect) " nipēhuāya "I started"
- Irrealis: -zquiya niquittāzquiya "I would have seen him/her/it" nipēhuazquiya "I would have started"
- Pluperfect: ca niquittaca "I had seen him" nipēuca "I had started
- Optative: cān niquittacān "would that I could see him" nipēucān "would that I could start"
- Admonitive: -(h)tin niquittatin "don't let me see him" nipēucatin "don't let me start" 
The applicative construction adds an argument to the verb. The role of the added argument can be benefactive, malefactive, indirect object or similar. It is formed by the suffix -lia.
- niquittilia "I see it for him"
The causative construction also adds an argument to the verb. This argument is an agent causing the object to undertake the action of the verb. It is formed by the suffix -tia.
- niquittatia "I make him see it/I show it to him"
Unspecified Subject/Passive 
The construction called "passive" by some grammarians and "unspecified subject construction" by others removes the subject from the valency of the verb, substituting it with a null reference, and promoting the argument marked by object prefixes to subject. The passive or unspecified subject construction uses one of two suffixes: -lo or -hua.
- quitta "he sees it"+ -lo= quittalo "it is seen (by someone)"
- miqui "he dies" + hua = micohua "there is dying/people are dying"
Directional affixes 
- -on- "away from the speaker"
- on+ tlahtoa "to speak" = ontlahtoa "he/she/it speaks towards there"
- -huāl- " towards the speaker"
- huāl+ tlahtoa "to speak" = huāllahtoa "he/she/it speaks towards here"
Introvert: Imperfective: -qui "comes towards the speaker in order to X" qui + itta "to see" + qui ="quittaqui "he/she/it will come here to see it" Perfective: -co "has come towards the speaker in order to X" qui + itta "to see" + co =quittaco "he/she/it has come here to see it"
Extrovert: Imperfective: -tīuh "goes away from the speaker in order to X" qui + itta "to see" + tīuh ="quittatīuh "he/she/it will go there to see it" Perfective: -to " has gone away from the speaker in order to X" qui + itta "to see" + to =quittato "he/she/it has gone there to see it"
A number of different suffixes exist to derive nouns from verbs:
- -lli used to derive passivized nouns from verbs.
tla "something" + ixca "roast" + l + tli = tlaxcalli "something roasted/ a tortilla"
tla + ihcuiloa "write/draw" + l - tli = tlahcuilolli "scripture/ a drawing"
- -liztli used to derive abstract nouns from verbs.
miqui "to die" + liztli = miquiliztli "death"
tlahcuiloa "to write something" + liztli = tlahcuiloliztli "the concept of writing or being a scribe"
- -qui used to derive agentive nouns from verbs.
ichtequi "to steal" + qui = ichtecqui "a thief"
tlahuāna "to become drunk" + qui = tlahuānqui "a drunkard"
- -ni used to derive habitual nouns from verbs.
miqui "to die" +ni = miquīni "a mortal"
cuacua "to bite" + ni = cuacuāni "someone that is known to be capable of or to habitually bite"
Verbal compounds 
Two verbs can be compounded with the ligature morpheme -ti-.
Relational Nouns and Locatives 
Spatial and other relations are expressed with relational nouns. Some locative suffixes also exist.
Noun Incorporation 
Noun incorporation is productive in Classical Nahuatl and different kinds of material can be incorporated.
The particle in is important in Nahuatl syntax and is used as a kind of definite article and also as a subordinating particle and a deictic particle, in addition to having other functions.
Classical Nahuatl can be classified as a non-configurational language, allowing many different kinds of word orders, even splitting noun phrases.
VSO basic wordorder 
The basic word order of Classical Nahuatl is verb initial and often considered to be VSO, although some scholars have argued for it being VOS. However, being non-configurational, all word orders are allowed and are used to express different kinds of pragmatic relations, such as thematization and focus.
Number system 
Classical Nahuatl has a vigesimal or base 20 number system. In the pre-Columbian Nahuatl script, the numbers 20, 400 (20²) and 8,000 (20³) were represented by a flag, a feather, and a bag, respectively.
Basic numbers 
|1||cē||Becomes cem- when prefixed to another element.|
|2||ōme||Becomes ōm- when prefixed to another element.|
|3||ēyi/yēi/ēi/yēyi||Becomes (y)ē- or (y)ēx- when prefixed to another element.|
|4||nāhui||Becomes nāhu-/nāuh- (i.e. /naːw/) when prefixed to another element.|
|5||mācuīlli||Derived from māitl "hand".|
|6||chicuacē||chicua- "5" + cē "1"|
|7||chicōme||chic- "5" + ōme "2"|
|8||chicuēyi||chicu- "5" + ēi "3"|
|9||chiucnāhui||chiuc- "5" + nāhui "4"|
|10||mahtlāctli||From māitl "hand" + tlāctli "torso".|
|20||cēmpōhualli||From cēm- "1" + pōhualli "a count" (from pōhua "to count").|
|400||cēntzontli||From cēn- "1" + tzontli "hair".|
|8000||cēnxiquipilli||From cēn- "1" + xiquipilli "bag".|
Compound numbers 
Multiples of 20, 400 or 8,000 are formed by replacing cēm- or cēn- with another number. E.g. ōmpōhualli "40" (2×20), mahtlāctzontli "4,000" (10×400), nāuhxiquipilli "32,000" (4×8,000).
The numbers in between those above—11 to 14, 16 to 19, 21 to 39, and so forth—are formed by following the larger number with a smaller number which is to be added to the larger one. The smaller number is prefixed with om- or on-, or in the case of larger units, preceded by īpan "on it" or īhuān "with it". E.g. mahtlāctli oncē "11" (10+1), caxtōlonēyi "18" (15+3), cēmpōhualmahtlāctli omōme "32" (20+10+2); cēntzontli caxtōlpōhualpan nāuhpōhualomōme "782" (1×400+15×20+4×20+2).
- -tetl for small, round objects (literally "rock")
- -pāntli for counting rows
- -tlamantli for foldable or stackable things
- -ōlōtl for roundish or oblong-shaped things (literally "maize cob")
Which classifier a particular object takes is loose and somewhat arbitrary.
Ordinal numbers 
- Andrews (2003): pp. 382–384; Carochi (2001): pp. 308–309; Lockhart (2001): pp. 69–70.
- Andrews (2003): p. 307.
- Andrews (2003): pp. 309–310.
- Andrews (2003): p. 310.
- Andrews (2003): p. 311.
- Andrews (2003): p. 312.
- Andrews (2003): pp. 311–312.
- Andrews (2003): pp. 312–313; Lockhart (2001): pp. 49–50.
- Andrews (2003): p. 316
- Andrews (2001): p. 452; Lockhart (2001): p. 50.
- Andrews, J. Richard (2003). Introduction to Classical Nahuatl (revised edition ed.). Norman: University of Oklahoma Press. ISBN 978-0-8061-3452-9.
- Carochi, Horacio (2001) . In Lockhart, James (ed. and trans.). Grammar of the Mexican language with an explanation of its adverbs. Stanford, CA: Stanford University Press. ISBN 0-8047-4281-2.
- Garibay K., Ángel María (1953). Historia de la literatura náhuatl. México D.F. (Spanish) (Nahuatl)
- Karttunen, Frances (1992). An analytical dictionary of Nahuatl. Norman: University of Oklahoma Press.
- Launey, Michel (1980). Introduction à la langue et à la littérature aztèques. Paris. (French) (Nahuatl)
- Launey, Michel (1992). Introducción a la lengua y a la literatura Náhuatl. México D.F.: UNAM. (Spanish) (Nahuatl)
- Lockhart, James (2001). Nahuatl as Written: lessons in older written Nahuatl, with copious examples and texts. Stanford, CA: Stanford University Press. ISBN 0-8047-4282-0.
- Molina, Alonso de (1992) . Vocabulario en Lengua Castellana y Mexicana y Mexicana y Castellana (Reprint ed.). México D.F.: Porrúa.
- Olmos, Andrés de (1993) . Arte de la lengua mexicana concluído en el convento de San Andrés de Ueytlalpan, en la provincia de Totonacapan que es en la Nueva España (Reprint ed.). México D.F.
- Rincón, Antonio del (1885) . Arte mexicana compuesta por el padre Antonio del Rincón (Reprint ed.). México D.F.
- Sahagún, Bernardino de (1950–71). In Charles Dibble and Arthur Anderson (eds.). Florentine Codex. General History of the Things of New Spain (Historia General de las Cosas de la Nueva España). vols I-XII. Santa Fe, NM.