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Linglib.Studies.AkinboFwangwar2026

Akinbo & Fwangwar (2026): Grammatical tones targeting ideophones #

[AF26]

Akinbo, S. K. & Fwangwar, T. R. (2026). Iconicity and expressiveness of grammatical tones targeting ideophones in Mwaghavul. Natural Language & Linguistic Theory 44:21.

Empirical claims #

  1. Grammatical tone targets ideophones. Mwaghavul derives verbs from ideophones via two segmentally null verbalisers with M and M-H tonal melodies as their sole exponents.

  2. Anchor + INTEGRITY OT analysis (paper §4.3, eq. 22). The tonal alternations are accounted for by morpheme-specific correspondence constraints ([Fin09b]): LEFT-ANCHOR-Tᵥ, RIGHT-ANCHOR-Tᵥ, INTEGRITY-Tᵥ, and MAX-Tone.

  3. Iconic Phonological Disharmony. In pluractional verbs, the M-H verbaliser realises M on every TBU of the reduplicant and H on every TBU of the base. This disharmony iconically marks "distinguishable identity" ([DT20]).

  4. Expressiveness survives integration. Derived ideophonic verbs retain expressive properties (affective meaning, nondisplaceability, ineffability) despite full morphosyntactic integration ([Pot07]-style secondary meanings), challenging the inverse correlation predicted by [DA17].

Substrate #

The OT analysis is built on Autosegmental.FloatingForm Syl TRN (Goldsmith-style autosegmental representation; built originally for [McPL26]). Each ulTier entry is one autosegment; surfaceLinks records associations between tier and TBUs. This represents spreading (one autosegment, multi-linked) and copying (multiple autosegments) as distinct objects — load-bearing for the INTEGRITY-Mᵥ constraint that rules out the copying variant of Tableau 24's optimum (paper p. 26 eq. 22c).

Constraint primitives come from Phonology/Tone/Constraints.lean, with Mwaghavul-specific anchor combinators defined in §2 below.

Section structure #

@[reducible, inline]

The Mwaghavul-instantiated autosegmental form.

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    The ideophone root (wùlàʃ in Tableau 24, háŋláyáp in Tableau 25). Both single-root tableaux share this morpheme.

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      The verbaliser. The M-tone verbaliser (Tableau 24) and the M-H verbaliser (Tableaux 25/26) share this morpheme — they're suppletive allomorphs of the same verbaliser per paper p. 20 eq. (17).

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        The reduplicant root in pluractional Tableau 26.

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          The base root in pluractional Tableau 26.

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            Wrap a Mwaghavul syllable as a TBU of the (single) ideophone root.

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              Wrap a syllable as a TBU of the reduplicant (Tableau 26).

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                Wrap a syllable as a TBU of the base (Tableau 26).

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                  L tone of the (single) ideophone root.

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                    M tone of the verbaliser.

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                      H tone of the verbaliser.

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                        L tone of the reduplicant root (Tableau 26).

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                          L tone of the base root (Tableau 26).

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                            Anchor + INTEGRITY + MAX-Tone constraints. Anchor constraints come in two flavours: - Single-root (lAnchToneC/rAnchToneC): scope over all TBUs. Correct for Tableaux 24/25 with one root morpheme. - Per-root, summed across roots (lAnchToneCAcross / rAnchToneCAcross): scope to each root morpheme separately, sum violations; if no root hosts the gram tone, every TBU of every targeted root counts (paper p. 28). Required for Tableau 26's two-root pluractional.

                            Does TBU i bear a tone of value t from morpheme m?

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                              L-ANCHOR-t-from-m: number of TBUs (in tier order) before the leftmost gram-t-from-m TBU. If no such TBU exists, every TBU counts (full TBU count).

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                                R-ANCHOR-t-from-m: counted from the right edge.

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                                  MAX-Tone (per autosegment): count of deleted ulTier entries. Matches paper p. 26 per-autosegment counting.

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                                    L-ANCHOR-Hᵥ for the verbaliser (paper p. 25 fn: H-tone version of eq. 22 has the same conditions).

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                                      A gram-t-from-m tone is realised on root rm iff some TBU of rm bears one.

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                                        L-ANCHOR scoped to root rm. 0 if t-from-m not realised on rm (per paper p. 28: "no violation to the other root morpheme"); else count TBUs of rm before the leftmost gram-t TBU of rm.

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                                          R-ANCHOR scoped to root rm.

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                                            L-ANCHOR summed across a list of root morphemes. If the gram tone is not realised on ANY of the roots, paper p. 28 assigns one violation per TBU of every targeted root (not 0).

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                                              R-ANCHOR summed across a list of root morphemes.

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                                                Paper Tableau 24 (p. 26): (wùlàʃ)₁ + Mᵥ. Six candidates including the copying variant (24f) that the paper rules out via INTEGRITY-Mᵥ.

                                                Encoding: ONE lex L autosegment multi-linked to both TBUs of the
                                                bisyllabic root (Goldsmith 1976 convention; paper notation
                                                `(wùlàʃ)₁` confirms a single morpheme-internal melody). 
                                                

                                                Faithful input: ulTier = [L_root (multi-linked), M_vbz (floating)].

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                                                  (24a) (wùlàʃ)₁ M₂: M still floating; L unchanged.

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                                                    (24e) ☞ (wūlāʃ)₂ SPREADING: M multi-linked to both TBUs; L deleted. ONE M autosegment, two surface links.

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                                                      (24f) (wū)₂(lāʃ)₂ COPYING: TWO separate M autosegments, each linked to one TBU. L deleted. Differs from (24a-e) in ulTier — the autosegmental representation has an extra M autosegment. INTEGRITY-Mᵥ fatally penalises this copying.

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                                                          (24a) profile [INTEG-Mᵥ, L-ANCH-Mᵥ, R-ANCH-Mᵥ, MAX-T] = [0, 2, 2, 0]: M floating, both anchors fail (no gram-M TBU), no deletions.

                                                          (24b) profile [0, 2, 2, 1]: M deleted, anchors fail, MAX-T fires.

                                                          (24c) profile [0, 1, 0, 0]: M on σ1; L-ANCH = 1 (M not at left).

                                                          (24d) profile [0, 0, 1, 0]: M on σ0; R-ANCH = 1 (M not at right).

                                                          (24e) ☞ profile [0, 0, 0, 1]: M multi-linked, anchors satisfied; INTEG = 0 (1 alive vbz M); MAX-T = 1 (L deleted). The unique optimum.

                                                          (24f) profile [1, 0, 0, 1]: TWO M autosegments → INTEG = 1 (fatal under the ranking, even though anchors and MAX-T tie with (24e)).

                                                          Headline: (24e) is the unique optimum under INTEG-Mᵥ ≫ L-ANCH-Mᵥ ≫ R-ANCH-Mᵥ ≫ MAX-Tone. The copying variant (24f) is ruled out by INTEGRITY; (24a-d) lose on anchors.

                                                          Paper Tableau 25 (p. 27): (háŋláyáp)₁ + M₂H₃ᵥ. Seven candidates; no INTEGRITY column (no copying variant arises). Encoding: ONE lex H autosegment multi-linked to all 3 TBUs (Goldsmith convention).

                                                          Faithful input: ulTier = [H_root (multi-linked), M_vbz, H_vbz].

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                                                            (25b) (hāŋlā)₂(yáp)₁: M on σ0-σ1; lex H on σ2; vbz H deleted.

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                                                              (25c) (háŋláyáp)₃: vbz H multi-linked to all TBUs; vbz M and lex H deleted.

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                                                                (25d) (hāŋlāyāp)₂: vbz M multi-linked to all TBUs; vbz H and lex H deleted.

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                                                                  (25e) ☞ (hāŋlā)₂(yáp)₃: vbz M on σ0-σ1; vbz H on σ2; lex H deleted. The winner.

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                                                                    (25f) (hāŋ)₂(láyáp)₃: vbz M on σ0; vbz H on σ1-σ2; lex H deleted.

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                                                                      (25g) (hāŋ)₂(lá)₁(yáp)₃: vbz M on σ0; lex H on σ1; vbz H on σ2. Lex H NOT deleted.

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                                                                          (25a) profile [3, 3, 3, 3, 2]: no verbaliser realised.

                                                                          (25b) profile [0, 3, 1, 3, 1]: vbz M docked left; vbz H deleted.

                                                                          (25c) profile [3, 0, 3, 0, 2]: vbz H spreading; vbz M deleted.

                                                                          (25d) profile [0, 3, 0, 3, 2]: vbz M spreading; vbz H deleted.

                                                                          (25e) ☞ profile [0, 0, 1, 2, 1]: M on σ0-σ1; H on σ2; lex H deleted. Winner.

                                                                          (25f) profile [0, 0, 2, 1, 1].

                                                                          (25g) profile [0, 0, 2, 2, 0]: lex H NOT deleted (still on σ1).

                                                                          Headline: (25e) is the unique optimum. (25a-d) lose on the top-tier anchors; (25f-g) tie with (25e) on top constraints but lose on R-ANCH-Mᵥ.

                                                                          Paper Tableau 26 (p. 28): (jàlpàt)₁ + (jàlpàt)₂ + M₃H₄ᵥ. Two root morphemes (reduplicant + base), each with /LL/ lexical melody (one L autosegment multi-linked to its 2 TBUs). The M-H verbaliser realises M on RED's TBUs and H on BASE's TBUs.

                                                                          Per-root anchoring (paper p. 28): if vbz M is realised on one root,
                                                                          the other root contributes no violation. If unrealised on both,
                                                                          every TBU of every targeted root counts. The
                                                                          `lAnchToneCAcross`/`rAnchToneCAcross` constraints in §2 implement
                                                                          this. 
                                                                          

                                                                          Faithful input: ulTier = [L_RED (multi-linked), L_BASE (multi-linked), M_vbz, H_vbz]. Each lex L is multi-linked to its own root's 2 TBUs.

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                                                                            (26b): vbz M on σ1 (rightmost of RED); vbz H on σ3 (rightmost of BASE); lex Ls survive on σ0 and σ2 respectively.

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                                                                              (26c): vbz M on σ0 (leftmost of RED); vbz H on σ2 (leftmost of BASE); lex Ls survive on σ1 and σ3.

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                                                                                (26d) ☞: M spreading on RED (both σ0, σ1); H spreading on BASE (both σ2, σ3); both lex Ls deleted. The winner — iconic M-on-RED

                                                                                • H-on-BASE pattern.
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                                                                                  (26e): vbz M on σ0; vbz H on σ1 (both within RED); lex L of BASE survives multi-linked. Lex L of RED deleted.

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                                                                                    (26f): vbz M spreading on RED + σ2 (first BASE TBU); vbz H on σ3.

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                                                                                      (26g): vbz M on σ0 (RED) + σ2 (BASE); lex L of RED on σ1; vbz H on σ3.

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                                                                                          Ranking, same shape as Tableau 25 but with per-root anchors: L-ANCH-Mᵥ ≫ R-ANCH-Hᵥ ≫ R-ANCH-Mᵥ ≫ L-ANCH-Hᵥ ≫ MAX-Tone.

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                                                                                            (26d) profile [0, 0, 0, 0, 2]: perfect realisation — vbz M on every TBU of RED, vbz H on every TBU of BASE. Both lex Ls deleted (MAX-T = 2).

                                                                                            Headline: (26d) is the unique optimum — the iconic M-on-RED + H-on-BASE disharmony pattern.

                                                                                            The Mwaghavul verbalisers are classified under [Rol18]'s grammatical-tone framework as replacive-dominant GT (Def 1): automatic replacement of the underlying tone within the valuation window of the target-host. Verbalisers are word-level + independent prosodic exponence (segmentally null — tone is the sole exponent).

                                                                                            M-tone verbaliser (VBZ₁) classified under Rolle 2018: replacive-dominant, word-level, independent.

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                                                                                              M-H verbaliser (VBZ₂).

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                                                                                                Both verbalisers are dominant: they neutralise the target's lexical tonal contrast.

                                                                                                The verbaliser-to-root relationship satisfies the dominant GT asymmetry, derived from CoP-scope: verbaliser is in Spec (dependent), root is in Head. Spec scopes over Head, so the asymmetry holds.

                                                                                                VBZ₁'s GTSpec.toSpec recovers the Spec used by deriveVerb.

                                                                                                VBZ₂'s GTSpec.toSpec recovers the Spec used by deriveVerb.

                                                                                                Cross-verb generalisations about the Mwaghavul ideophone-to-verb derivation (paper §3, summarised in eq. (13)). These are properties of the data, decidable from the Ideophone records in Fragments/Mwaghavul/Basic.lean.

                                                                                                The M-H tonal melody is attested only in derived verbs (paper eq. 13e). No underived Mwaghavul verb has M-H. We test against the concrete ideophone data.

                                                                                                Mwaghavul satisfies [Hym06]'s tonal-language definition (3): "an indication of pitch enters into the lexical realisation of at least some morphemes."

                                                                                                The segmentally null verbalisers that trigger the tonal alternations are instances of the verbal categoriser v in Distributed Morphology ([Mar97], [Har14b]). The ideophonic base (noun, adjective, or adverb) is recategorised as a verb through merger with v, whose sole phonological exponent is a tonal melody.

                                                                                                [AF26] §4.2 argues that derived ideophonic verbs retain [Pot07]-style expressive properties despite morphosyntactic integration: affective meaning, nondisplaceability, descriptive ineffability, context-dependence. This challenges [DA17]'s prediction of inverse correlation between integration and expressiveness.

                                                                                                Derived ideophonic verbs exhibit all canonical expressive properties: independent, nondisplaceable, perspective-dependent, descriptively ineffable, immediate, repeatable, no perspective shift, no discourse antecedent required.

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                                                                                                  General dominant-cophonology ↔ overwrite agreement ([Rol18]) #

                                                                                                  The per-tableau agreement theorems in the Tableau24/25/26 sections above are instances of a general result: the two parallel formalisms for dominant grammatical tone in [Rol18] — direct tonalOverwrite and constraint-based cophonologicalEval under a subranking promoting MxBM-C (basemap faithfulness) — coincide. When MxBM-C is top-ranked, OT evaluation necessarily selects basemap-faithful candidates, which are exactly the tonalOverwrite outputs. The proof chain goes through optimal_zero_first (OT substrate): a candidate with 0 violations on the top constraint forces every optimal candidate to 0.

                                                                                                  theorem AkinboFwangwar2026.dominant_coph_selects_basemap_faithful {L C : Type} [DecidableEq L] [DecidableEq C] (basemapTier : List Tone.TRN) (extractTier : CList Tone.TRN) (l : L) (defaultRanking : List (L × Constraints.Constraint C)) (candidates : List C) (h : candidates []) (hLen : ccandidates, (extractTier c).length = basemapTier.length) (hFaithful : ccandidates, extractTier c = basemapTier) :
                                                                                                  have mxbmc := Rolle2018.mkBasemapConstraint basemapTier extractTier; cOptimalityTheory.Cophonology.cophonologicalEval defaultRanking [(l, mxbmc)] candidates h, extractTier c = basemapTier

                                                                                                  The general agreement theorem: when MxBM-C (basemap faithfulness) is in the cophonological subranking, every OT-optimal candidate is basemap-faithful — its tonal tier exactly matches the basemap output.

                                                                                                  This is the mathematical core of [Rol18] Ch 5: dominant GT is not a special rule but a consequence of promoting a faithfulness constraint. The constraint forces the matrix output to correspond to the basemap output, which is independent of the target's underlying tones (basemapOutput_tone_independent_whole).

                                                                                                  theorem AkinboFwangwar2026.dominant_coph_agrees_with_tonalOverwrite {S L C : Type} [DecidableEq S] [BEq S] [Repr S] [DecidableEq L] [DecidableEq C] (host : List (Tone.TBU S)) (t defaultTone : Tone.TRN) (extractTier : CList Tone.TRN) (l : L) (defaultRanking : List (L × Constraints.Constraint C)) (candidates : List C) (h : candidates []) (hLen : ccandidates, (extractTier c).length = (Rolle2018.tonalTier (Rolle2018.basemapOutput host { name := "", melody := [t], window := Tone.ValuationWindow.whole } defaultTone)).length) (hFaithful : ccandidates, extractTier c = Rolle2018.tonalTier (Rolle2018.basemapOutput host { name := "", melody := [t], window := Tone.ValuationWindow.whole } defaultTone)) :
                                                                                                  have spec := { name := "", melody := [t], window := Tone.ValuationWindow.whole }; have baseTier := Rolle2018.tonalTier (Rolle2018.basemapOutput host spec defaultTone); have mxbmc := Rolle2018.mkBasemapConstraint baseTier extractTier; cOptimalityTheory.Cophonology.cophonologicalEval defaultRanking [(l, mxbmc)] candidates h, extractTier c = Rolle2018.tonalTier (Tone.tonalOverwrite host spec)

                                                                                                  Dominant cophonology agrees with tonalOverwrite: for whole-word single-tone replacement, OT evaluation under the dominant cophonology selects candidates whose tonal tier matches the direct tonalOverwrite operation. The connection goes through tonalOverwrite_basemap_faithful: the tonalOverwrite output equals the basemap output, and dominant_coph_selects_basemap_faithful ensures the OT evaluation selects exactly the basemap-faithful candidates.