Manambu Medial Clause Markers @cite{aikhenvald-2008}

Medial clause markers (clause chain linkers) in Manambu (Ndu family, East Sepik, Papua New Guinea). Data from @cite{aikhenvald-2008} and @cite{sarvasy-aikhenvald-2025}.

Manambu has a rich system of medial clause markers that encode:

1. Switch-reference: SS (same subject) vs. DS (different subject), or neutral
2. Temporal/logical relation: completive, cotemporaneous, immediate sequence, reason, condition
3. Subject agreement: some DS markers trigger subject agreement on the medial verb; SS markers do not

Inventory (@cite{sarvasy-aikhenvald-2025}: Table 3)

Form	SR	Meaning	Subject marking
-ku	SS	temporal completive 'after'	no
-k	DS	reason, real condition	yes
-ta:y	SS	cotemporaneous 'while'	no
-taka	SS	immediate sequence 'as soon as, just as'	no
-kab	DS	brief temporal overlap 'as soon as'	yes
-ta:y-kab	SS	brief temporal overlap 'as soon as'	no
-lak	neutral	reason, consequence 'because, so'	yes
-ga:y	SS	unlikely condition 'if'	no
-n	neutral	sequential or simultaneous, manner	no

inductive Fragments.Manambu.MedialVerbs.SRValue : Type

Switch-reference value on a medial clause marker.

• ss : SRValue
• ds : SRValue
• neutral : SRValue

instance Fragments.Manambu.MedialVerbs.instDecidableEqSRValue : DecidableEq SRValue

Equations

• Fragments.Manambu.MedialVerbs.instDecidableEqSRValue x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯

def Fragments.Manambu.MedialVerbs.instReprSRValue.repr : SRValue → Nat → Std.Format

Equations

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instance Fragments.Manambu.MedialVerbs.instReprSRValue : Repr SRValue

Equations

• Fragments.Manambu.MedialVerbs.instReprSRValue = { reprPrec := Fragments.Manambu.MedialVerbs.instReprSRValue.repr }

instance Fragments.Manambu.MedialVerbs.instBEqSRValue : BEq SRValue

Equations

• Fragments.Manambu.MedialVerbs.instBEqSRValue = { beq := Fragments.Manambu.MedialVerbs.instBEqSRValue.beq }

def Fragments.Manambu.MedialVerbs.instBEqSRValue.beq : SRValue → SRValue → Bool

Equations

• Fragments.Manambu.MedialVerbs.instBEqSRValue.beq x✝ y✝ = (x✝.ctorIdx == y✝.ctorIdx)

def Fragments.Manambu.MedialVerbs.instInhabitedSRValue.default : SRValue

Equations

• Fragments.Manambu.MedialVerbs.instInhabitedSRValue.default = Fragments.Manambu.MedialVerbs.SRValue.ss

instance Fragments.Manambu.MedialVerbs.instInhabitedSRValue : Inhabited SRValue

Equations

• Fragments.Manambu.MedialVerbs.instInhabitedSRValue = { default := Fragments.Manambu.MedialVerbs.instInhabitedSRValue.default }

structure Fragments.Manambu.MedialVerbs.MarkerEntry : Type

A medial clause marker entry in Manambu.

• form : String

  Morphological form (suffix on the medial verb).

• sr : SRValue

  Switch-reference value.

• gloss : String

  Semantic relation gloss.

• hasSubjectMarking : Bool

  Whether subject agreement appears on the medial verb with this marker.

instance Fragments.Manambu.MedialVerbs.instReprMarkerEntry : Repr MarkerEntry

Equations

• Fragments.Manambu.MedialVerbs.instReprMarkerEntry = { reprPrec := Fragments.Manambu.MedialVerbs.instReprMarkerEntry.repr }

def Fragments.Manambu.MedialVerbs.instReprMarkerEntry.repr : MarkerEntry → Nat → Std.Format

Equations

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def Fragments.Manambu.MedialVerbs.instBEqMarkerEntry.beq : MarkerEntry → MarkerEntry → Bool

Equations

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• Fragments.Manambu.MedialVerbs.instBEqMarkerEntry.beq x✝¹ x✝ = false

instance Fragments.Manambu.MedialVerbs.instBEqMarkerEntry : BEq MarkerEntry

Equations

• Fragments.Manambu.MedialVerbs.instBEqMarkerEntry = { beq := Fragments.Manambu.MedialVerbs.instBEqMarkerEntry.beq }

def Fragments.Manambu.MedialVerbs.ku : MarkerEntry

-ku: SS, temporal completive 'after'. No subject marking.

Equations

• Fragments.Manambu.MedialVerbs.ku = { form := "-ku", sr := Fragments.Manambu.MedialVerbs.SRValue.ss, gloss := "after (completive)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.k : MarkerEntry

-k: DS, reason or real condition. Subject marking on medial verb.

Equations

• Fragments.Manambu.MedialVerbs.k = { form := "-k", sr := Fragments.Manambu.MedialVerbs.SRValue.ds, gloss := "reason/real condition", hasSubjectMarking := true }

def Fragments.Manambu.MedialVerbs.tay : MarkerEntry

-ta:y: SS, cotemporaneous 'while'. No subject marking.

Equations

• Fragments.Manambu.MedialVerbs.tay = { form := "-ta:y", sr := Fragments.Manambu.MedialVerbs.SRValue.ss, gloss := "while (cotemporaneous)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.taka : MarkerEntry

-taka: SS, immediate sequence 'as soon as, just as'. No subject marking.

Equations

• Fragments.Manambu.MedialVerbs.taka = { form := "-taka", sr := Fragments.Manambu.MedialVerbs.SRValue.ss, gloss := "as soon as (immediate sequence)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.kab : MarkerEntry

-kab: DS, brief temporal overlap 'as soon as'. Subject marking present.

Equations

• Fragments.Manambu.MedialVerbs.kab = { form := "-kab", sr := Fragments.Manambu.MedialVerbs.SRValue.ds, gloss := "as soon as (brief overlap)", hasSubjectMarking := true }

def Fragments.Manambu.MedialVerbs.tayKab : MarkerEntry

-ta:y-kab: SS, brief temporal overlap 'as soon as'. No subject marking. Morphologically complex: cotemporaneous -ta:y + overlap -kab.

Equations

• Fragments.Manambu.MedialVerbs.tayKab = { form := "-ta:y-kab", sr := Fragments.Manambu.MedialVerbs.SRValue.ss, gloss := "as soon as (brief overlap)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.lak : MarkerEntry

-lak: neutral (not SR-sensitive), reason/consequence 'because, so'. Subject marking present.

Equations

• Fragments.Manambu.MedialVerbs.lak = { form := "-lak", sr := Fragments.Manambu.MedialVerbs.SRValue.neutral, gloss := "because/so (reason/consequence)", hasSubjectMarking := true }

def Fragments.Manambu.MedialVerbs.gay : MarkerEntry

-ga:y: SS, unlikely condition 'if (unlikely)'. No subject marking.

Equations

• Fragments.Manambu.MedialVerbs.gay = { form := "-ga:y", sr := Fragments.Manambu.MedialVerbs.SRValue.ss, gloss := "if (unlikely condition)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.n : MarkerEntry

-n: neutral (not SR-sensitive), sequential or simultaneous action, manner. No subject marking. The most semantically general medial marker.

Equations

• Fragments.Manambu.MedialVerbs.n = { form := "-n", sr := Fragments.Manambu.MedialVerbs.SRValue.neutral, gloss := "and/while/by (sequential/simultaneous/manner)", hasSubjectMarking := false }

def Fragments.Manambu.MedialVerbs.allMarkers : List MarkerEntry

All medial clause markers.

Equations

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def Fragments.Manambu.MedialVerbs.ssMarkers : List MarkerEntry

SS markers.

Equations

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def Fragments.Manambu.MedialVerbs.dsMarkers : List MarkerEntry

DS markers.

Equations

• One or more equations did not get rendered due to their size.

def Fragments.Manambu.MedialVerbs.neutralMarkers : List MarkerEntry

Neutral markers (not SR-sensitive).

Equations

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def Fragments.Manambu.MedialVerbs.markersWithSubjAgreement : List MarkerEntry

Markers that trigger subject agreement.

Equations

• Fragments.Manambu.MedialVerbs.markersWithSubjAgreement = List.filter (fun (x : Fragments.Manambu.MedialVerbs.MarkerEntry) => x.hasSubjectMarking) Fragments.Manambu.MedialVerbs.allMarkers

theorem Fragments.Manambu.MedialVerbs.marker_count : allMarkers.length = 9

9 medial clause markers in total.

theorem Fragments.Manambu.MedialVerbs.ss_count : ssMarkers.length = 5

5 SS markers.

theorem Fragments.Manambu.MedialVerbs.ds_count : dsMarkers.length = 2

2 DS markers.

theorem Fragments.Manambu.MedialVerbs.neutral_count : neutralMarkers.length = 2

2 neutral markers.

theorem Fragments.Manambu.MedialVerbs.sr_partition : ssMarkers.length + dsMarkers.length + neutralMarkers.length = allMarkers.length

9 = 5 + 2 + 2: SS + DS + neutral exhausts the inventory.

theorem Fragments.Manambu.MedialVerbs.ss_no_subject_marking : (ssMarkers.all fun (x : MarkerEntry) => !x.hasSubjectMarking) = true

No SS marker triggers subject agreement.

theorem Fragments.Manambu.MedialVerbs.ds_has_subject_marking : (dsMarkers.all fun (x : MarkerEntry) => x.hasSubjectMarking) = true

Every DS marker triggers subject agreement.

theorem Fragments.Manambu.MedialVerbs.subject_marking_implies_not_ss : (markersWithSubjAgreement.all fun (x : MarkerEntry) => x.sr != SRValue.ss) = true

Subject marking correlates with DS or neutral status: it never appears with SS. This reflects the structural logic — when subjects are the same, marking the subject on the medial verb would be redundant.