Chapter 36Verbal Subclasses: A Valence-Based Word-Class Taxonomy

36.1 A valence-based taxonomy

Verbs are the class of words that head clausal predicates and carry person-marking for their arguments Nakagawa (2024: 116); Satō (2008: 2). The class inventory and its formal diagnostics are established in Chapter 33 (The Word-Class Inventory and the Noun/Verb Bipartition). Within the verbal class, Nakagawa organizes the subclasses along two partially independent axes: argument count (how many core nominal arguments the verb governs) and affix set (which portion of the person paradigm the verb admits) Nakagawa (2024: 116–117); Nakagawa (2022: 473). Satō (2008: 2–3) works within the same bipartite framework with slightly different labelling; both follow the scheme of (Tamura 2000). Refsing (1986: 74–76) places Ainu verbs in a broader macro-class (Verbals) that covers what the present taxonomy separates into intransitive, transitive, and copular verbs, without further subdivision by valence internally. The pedagogical account in Ijäs (2023) uses the person-affix set as its primary classificatory criterion, organizing the verb inventory in the same way.

Two further structural types cross-cut the table: locative-object verbs (場所目的語動詞), which take a locative phrase in the O position, and serial predicates (連動詞), in which two stems share argument slots. Both are introduced below and described in depth in Chapter 57 (Transitivity, Valence Classes, and Ambitransitivity). The valency-changing morphology that moves verbs between classes — applicatives, causative affixes, the antipassive prefix i-, and the transitivizer -ka — is treated in Chapter 73 (Valency, Voice, and Noun Incorporation: Overview).

36.2 The person-marking diagnostic

Assigning a verb to a subclass amounts to determining which argument roles its affixes encode. The Hokkaido Ainu personal-affix paradigm distinguishes three roles: S (sole argument of an intransitive), A (subject of a transitive), and O (object of a transitive). The full paradigm and its mixed alignment are set out in Chapter 62 (Architecture of the Personal-Affix System: The Four Persons and the S/A/O Paradigms); what matters here is its use as a classificatory probe. A verb whose subject takes S affixes and permits no O affix is intransitive. A verb whose subject takes A affixes and whose object takes O affixes is transitive. A verb that takes A affixes on its subject but licenses no O-affix slot is copular.

The first singular provides the sharpest probe because 1SG distinguishes S=A (ku=) from O (en=). At fourth person the contrast is still more transparent: the intransitive subject bears the suffix =an, the transitive subject the prefix a=, and the transitive object the prefix i= — three distinct exponences for three distinct roles Nakagawa (2024: 163–167); Bugaeva (2012: 471–472).

Subclass membership is grammatical, not semantic. The verb ramu ‘think about (something)’ is transitive — it licenses A and O affixes — even though its meaning is stative. The verb yaynu ‘think, feel (intransitively)’ is intransitive for the same semantic domain. The diagnostic difference is purely morphological. This contrast was highlighted in community discussion: *sekor a=ramu an is ungrammatical because ramu requires the transitive A prefix a=, not the intransitive S suffix =an aynu-corpora Discord (2023–2026) (nukopoli, 2024-11-09) ‹corpus-confirmed›.

36.3 Intransitive verbs

One-place predicates assign a single S role. The class is large and semantically heterogeneous: it encompasses motion predicates (arpa ‘go’, ek ‘come (SG)’, san ‘go down, go out’, ahun ‘go in, enter’), postural predicates (as ‘stand’), cognitive and emotional predicates (mina ‘laugh’, yaynu ‘think, feel’), and the large class of property predicates (pirka ‘be good’, poro ‘be big’, hure ‘be red’, tanne ‘be long’) that in other languages would be adjectives. All share the S affix set; no O slot is available.

Property predicates — stative predicates describing qualities or states — take the identical S affixes as action intransitives, and head bare predicates without a copula. The third person is zero, so a property verb in a simple declarative clause carries no overt person affix:

The argument for treating property predicates as intransitive verbs rather than as a separate adjective class — and the morphological evidence for that analysis — is developed in Chapter 37 (The 'No Adjective Class' Thesis: Property Concepts as Stative Verbs). The predication of property concepts without a copula is treated in Chapter 99 (Property-Concept (Adjectival) Predication without a Copula).

Within the intransitive class the descriptive literature distinguishes two semantic groupings: agentive intransitives, whose S argument is volitional and agent-like (motion, action, and activity predicates), and patientive intransitives, whose S argument is an experiencer or the subject of a state (property predicates, involuntary experience verbs). The basic person-affix paradigm does not encode this contrast morphologically: both groupings select the same S affix set across all persons Nakagawa (2024: 126–127). The agreement system is therefore not split-intransitive in the morphological sense — S-set assignment depends only on valence, not on the agent-vs-patient character of the S argument. Whether semantic or lexical criteria support a deeper Split-S or Fluid-S analysis ‹contested› is examined in Chapter 71 (The Split-Intransitive (Active–Stative) Core) and Chapter 72 (Tripartite, Nominative-Accusative, and the Central Alignment Debate).

36.4 Transitive verbs

Two-place predicates assign an A role to their subject and an O role to their object. When both arguments are non-third-person, each may be person-indexed on the verb. The ceiling is two indexes per verb — one A index and one O index — and a third argument is never indexed Nakagawa (2024: 125–127); Satō (2025: 361). Third-person arguments surface as bare noun phrases.

One morphological consequence of transitivity is that verbal number marks plurality of the object, not the subject. The suppletive pair rayke ‘kill (O.SG)’ and ronnu ‘kill (O.PL)’ signals how many entities are killed, regardless of how many kill: the intransitive S and the transitive O are treated alike for number marking, in an ergative-like pattern aynu-corpora Discord (2023–2026) (nukopoli, 2023-12-12) ‹consensus›. The full system of number-sensitive stems and the pluractional suffix -pa are treated in Chapter 58 (Verbal Number: Suppletive Stems and the Pluractional -pa).

36.5 Three-place verbs

A lexically small set of predicates takes three argument slots: subject (A), a primary object (typically a recipient or addressee), and a secondary object (typically a theme or propositional content). The principal members are kore ‘give’, ye ‘say to’, and kar ‘make for someone’, along with morphologically complex forms derived from them Satō (2023); Bugaeva & Kobayashi (2022); Kobayashi (2015).

Because the verb carries at most two person indexes, the second object is unindexed when it is third person. The indexed O slot falls on the recipient or the more animate participant; the theme or propositional content remains a bare noun phrase. When both non-subject arguments are third person, only A is indexed:

A related pattern arises with the serial construction aske uk ‘invite (lit. take someone's hand)’: its A role indexes on the action verb uk ‘take, receive’ while the recipient role indexes on the relational noun aske ‘hand (in grip)’, giving en=aske e=uk 'you invite me'. Satō calls this type 連他動詞 (serial transitive); it is the clearest case of a wider class of serial predicates in which argument slots are shared between adjacent stems Satō (2008: 147); aynu-corpora Discord (2023–2026) (nukopoli, 2024-11-17) ‹corpus-confirmed›.

Whether the language is best analysed as secondary-object or secundative for this argument pattern, and how three-place structure interacts with applicative morphology, is taken up in Chapter 57 (Transitivity, Valence Classes, and Ambitransitivity) and Chapter 66 (Object Indexing: Monotransitive and Ditransitive Clauses).

36.6 The copula and the existential verbs

Three predicates hold a special position in the taxonomy: the copula ne ‘be, become (copula)’, the existentials an ‘exist, be’ and oka ‘exist, be’, and the negative existential isam ‘not exist, be absent’. They function as predication operators and each admits a distinctive affix set.

The copula ne ‘be, become’ heads equative and classificatory clauses of the structure [NP_subject — NP_predicate — ne]. Its affix behaviour places it with the transitive class: the subject takes A-type affixes, not S. At first singular this means ku=ne 'I am X', with the same prefix ku= that marks the A of a transitive verb. The predicate nominal, however, carries no O person index regardless of its person or number. Nakagawa groups this under a separate copular affix set — alongside the intransitive and transitive sets — precisely because it is A-marked on the subject yet has no object-affix slot Nakagawa (2024: 116–117); Satō (2008: 2–3).

The copula also covers the translative reading 'become X': the same form serves both equative and inceptive predication in context Nakagawa (2024: 118–119). The full treatment of copular predication and its TAM and evidential extensions is in Chapter 96 (The Copula ne and Predicate-Nominal Clauses).

The existential an ‘exist, be’ is strictly intransitive. It takes S affixes, and the located entity is its S argument; the locative phrase specifying the location is an oblique adjunct, not an O. The diagnostic contrast with the transitive existential-locative un ‘be located in/at (vt)’ is crisp: an requires a locative-case frame (cise or ta an 'is in the house'), while un takes the location as a direct O and may carry an O person affix aynu-corpora Discord (2023–2026) (nukopoli, 2024-11-09) ‹corpus-confirmed›. The existential paradigm — an, oka, and their progressive and resultative extensions — is treated in Chapter 97 (Existential and Locational Clauses (an / oka)).

The negative existential isam ‘not exist, be absent’ predicates non-existence of its S argument. In possession frames it serves as the negative counterpart of kor ‘have, possess’. Its inflection and possessed-construction interaction are treated in Chapter 127 (Negative Existential and Possessive: isam) and Chapter 98 (Predicative Possession: kor, Existential Possession, and isam).

One community observation bears noting: in certain negative frames (ka somo ne 'it is not the case that…') and occasionally elsewhere, ne appears without a person affix. The reason is not settled in the accessible sources aynu-corpora Discord (2023–2026) (nukopoli, 2023-12-25) ‹speculative›. The negation–copula interaction is discussed in Chapter 96 (The Copula ne and Predicate-Nominal Clauses).

36.7 Avalent predicates

Nakagawa's arity framework reserves a zero-place (完全 / 0項) category for predicates that take no referential core argument Nakagawa (2024: 116–117). The category is defined formally: a zero-place predicate has no argument-affix slot, not merely an impersonal or unspecified subject. On the arity account, a clause whose total argument count resolves to zero takes a complementizer rather than heading a relative-clause nominalization Nakagawa (2024: 504), which connects this class to the complementizer-vs-nominalizer distinction treated in Chapter 101 (The Nominalizers -p/-pe and -i/-hi (Participant, Event, Place, Fact)).

The sources read for this chapter did not bank specific lexical members of the zero-place class Nakagawa (2024: 116–117). A fuller inventory and the syntactic treatment of avalent predicates — including weather expressions and impersonal event frames — are provided in Chapter 57 (Transitivity, Valence Classes, and Ambitransitivity).

36.8 Locative-object verbs and ambitransitives

Two structural types cut across the valence-based taxonomy and have word-class consequences.

Locative-object verbs (場所目的語動詞) take a locative noun phrase in the structural position of the O argument, and the locative receives an O-type person affix in the paradigm. The subject of these verbs takes A affixes, making them transitive in their affix behaviour even though their object is a location rather than an entity. The valency of verbs taking place or space as an argument is examined in Kobayashi (2020); Nakagawa (2024: 116–117).

Ambitransitive patterns arise where the same stem alternates between an S-marked (intransitive) frame and an A-marked (transitive) frame depending on whether an O argument is present. The alternation is closely related to the productivity of denominal and deverbal derivation: Ainu intransitive verbs freely convert to noun-modifying and compound-forming roots, and transitivisers can reinstate a transitive frame Nakagawa (2024: 267–272); Satō (2016).

Both types, and the full inventory of valency-alternating morphology, are described in Chapter 57 (Transitivity, Valence Classes, and Ambitransitivity). The applicative system that promotes locatives into O position is treated in Chapter 78 (The Applicative System: Overview and the Preverb-vs-Applicative Debate), and the antipassive that converts transitives to intransitives in Chapter 83 (The Antipassive / Detransitive i-).