Article

Numeral Formation in Ígálâ: Morphological Structure, Arithmetic Logic, and Typological Insights

Salem Ochala Ejeba 1
Author Information & Copyright
1University of Port Harcourt, Nigeria
Corresponding Author : Salem Ochala Ejeba Senior Lecturer, Department of Linguistics and Language Arts, University of Port Harcourt, Nigeria Email: salem.ejeba@gmail.com

Copyright © 2025 Language Research Institute, Sejong University. Journal of Universal Language is an Open Access Journal. All articles are distributed online under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jun 26, 2025; Revised: Aug 28, 2025; Accepted: Sep 15, 2025

Published Online: Sep 30, 2025

Abstract

This paper offers the first detailed typological account of the numeral system of Ígálâ, a West Benue-Congo language of Nigeria, addressing a longstanding gap in descriptive and comparative research. Drawing on native-speaker data, elicitation, and textual sources, the study shows how Ígálâ encodes arithmetic through systematically organized morphological and syntactic processes. Numerals up to ten have distinct lexical forms, while eleven to nineteen follow a quasi-decimal additive pattern. From twenty upward, the system is fundamentally vigesimal, with higher numerals constructed through multiplication anchored on twenty and fifty, and extended by additive combinations and recursive stacking. The vigesimal optimum, which caps multiplication at nineteen, yields forms that are both cognitively transparent and typologically coherent. Borrowed items from Hausa and English occur mainly in monetary contexts and remain structurally peripheral. Overall, the Ígálâ evidence not only affirms the vigesimal base as the organizing principle of the system but also sharpens our understanding of Greenbergian universals, showing how high-before-low ordering can be maintained with unusual consistency across operations. The system is thus both theoretically significant for crosslinguistic models of numeral typology and practically relevant for orthographic standardization and language pedagogy.

Keywords: Ígálâ language; numeral system; vigesimal base; numeral morphology; West Benue-Congo

1. The Concept of a Numeral System

A numeral system comprises a language’s counting words and the rules governing their formation (Trask 1997). Hammarström (2010) describes numerals as conventional spoken forms that denote exact quantities across object types and social contexts, shared by the entire speech community. Numerals function as cardinals, ordinals, nominals, and sequence markers (Corver et al. 2007), and their recursive morphology can in principle generate infinite values (Booij 2010).

Cross-linguistically, numeral systems are self-contained yet systematic components of grammar (Hurford 1999), structured around base values and operations such as addition and multiplication (Welmers 1974). While many emerge from embodied practices like finger-counting, others extend into abstract domains of measure and time (Payne 1997, Omachonu 2011). This study describes the morphological structure of the Ígálâ numeral system and situates it within broader typologies. As a West Benue-Congo language closely related to Yoruba and Itsekiri (Akinkugbe 1976, Capo 1989), Ígálâ exemplifies both a coherent internal logic and the cultural reasoning encoded in number words.

2. A Cross-Linguistic Exploration of Numeral Systems

Cross-linguistic research shows both diversity and convergence in numeral systems, which encode arithmetic operations, morphosyntax, and cultural conventions. In West Africa, Welmers (1974) highlights multiplicative constructions in Akan, where ńná “and” marks addition, and the highly vigesimal Yoruba system, which combines additive, subtractive, and multiplicative strategies (e.g., seventy-five = four twenties minus five), with higher bases such as 200 and 400. Comparable strategies occur elsewhere: French retains vigesimal remnants (quatre-vingt-dix ‘90’), Latin employs subtraction (undecim ‘11’), Yukatek Maya builds on powers of twenty, and Nuuchahnulth mixes decimal and vigesimal forms while allowing numeral incorporation into verbs. Typological surveys (Hurford 1975, Gvozdanović 1999, Haspelmath et al. 2005, Stonham 2007) show base numerals (10, 20, 60) as universal anchors shaped by cognition and culture. Against this backdrop, Ígálâ stands out for its coherent vigesimal-multiplicative logic, where base units, operations, and morphosyntax form an integrated system, enriching both West African typology and the comparative study of numerical cognition.

Yakub et al. (2021) argue that linguistic description must attend to the internal organization of categories if their communicative force is to be understood. Comrie (2020), in reassessing Greenberg’s claims about numeral systems, reinforces this point by showing that while descending order is widespread, other languages display ascending (Khmer), mixed (German), and vigesimal (Welsh, Breton, French) patterns, each reflecting its own structural logic. Alphonce (2023) adds that such logics are vulnerable to language contact, as seen in the replacement of Alagwa and Burunge numerals by Swahili, which undermines intergenerational transmission. Across these studies, the principle is clear: crosslinguistic comparison must rest on the structural and functional specificities of linguistic categories, even when they are pressured by dominant lingua francas.

2.1. Literature on Ígálâ Numerals

Ígálâ is a West Benue Congo language spoken majorly in Kogi State, Nigeria by the Igala ethnic group (Ejeba 2020). Earlier works on numerals in the language (Etu 1999, Ocheja 2001) emphasize lexical reform over structural analysis, differing mainly on the form for ‘100’ (ólíú vs. íchányí). Both overlook the vigesimal logic of the system, treating numerals as static items rather than constructions of addition, multiplication, and subtraction, a concern noted by Ekundayo (1971) and Welmers (1974). Omachonu (2011) advocates decimal reform, claiming the system “did not go beyond one thousand” (2011: 84), a ceiling inconsistent with evidence that vigesimal systems extend much higher (Hurford 1975, Haspelmath et al. 2005). While reflecting modernization concerns, such approaches risk obscuring the coherence of the indigenous system. The present study therefore offers a descriptive account of Ígálâ numerals, analyzing their structural strategies and situating them within cross-linguistic typologies (cf. Gvozdanović 1999, Stonham 2007).

2.2. Methods in the Description of Ígálâ Numerals

Data for this study were obtained from naturally occurring speech events, supplemented by native-speaker intuition. The researcher, a native speaker of the Dekina dialect of Ígálâ, provided direct linguistic access and internal validation. Examples are presented in tabular format and analyzed through morpheme-by-morpheme glossing, in keeping with the Leipzig Convention for interlinear glossing (Max Planck Institute for Evolutionary Anthropology 2015). Glossing prioritizes morphosyntactic structure over phonological realization. Orthographic conventions follow Miachi and Armstrong (1986), with subsequent modifications proposed in Ejeba (2016). Tone is represented as high (´), low (`), and mid (unmarked). The study adopts a descriptive methodology, providing an overview of the Ígálâ numeral system and examining its morphological and grammatical strategies for encoding numerical relations.

3. The Ígálâ Numeral System

As noted in Section 2, numeral systems vary cross-linguistically in base structures and grammatical strategies. In traditional Ígálâ society, where counting needs were modest, devices such as finger-counting, twigs, kola nuts, or cowries sufficed. Larger quantities were often expressed metaphorically, as in ìlẹ̀ fíá tẹ́ “a mammoth crowd,” literally “the world scattered in place,” ùjẹnwu lọ̀ ómi lọ̀ ẹ̀kẹ̀tẹ̀ “more than enough food,” literally “food rained water rained and sand,” or ọ́kọ́ gwúdọ gwùdọ “an exceedingly large sum of money,” literally “nonsense nonsense money.”

Such strategies met the needs of a subsistence economy, but modern contexts demand greater numerical precision. This raises a typological question: is the Ígálâ system merely a rudimentary tool for basic arithmetic, or a structurally complex system that integrates decimal and vigesimal logics? This study answers by presenting a paradigm of Ígálâ numerals from zero to indefinitely large values, tracing additive, multiplicative, and subtractive strategies, examining borrowing, and situating the system within broader cognitive and typological frameworks. The analysis shows the system to be not only arithmetically robust but also structurally coherent and culturally significant.

Ígálâ numerals are organized through the interplay of additive, multiplicative, and subtractive principles, with base-10 and base-20 interacting in systematic ways. Table 1 presents the paradigm from 0 to 1,000 (and beyond), illustrating both morphological composition and semantic logic.

Table 1. Paradigm of Ígálâ Numerals (0–10,000)
Numeral Expression Literal Breakdown Notes
0 òfo Zero Also means “nullity, emptiness”
1 ényẹ́, ǒkâ, òké 1 Variant forms
2 èjì 2 With prefix: òkémọ́èjì
3 ẹ̀ta 3 With prefix: òkémọ́ẹ̀ta
4 ẹ̀lẹ̀ 4 With prefix: òkémọ́ẹ̀lẹ̀
5 ẹ̀lú 5 With prefix: òkémọ́ẹ̀lú
6 ẹ̀fà 6 With prefix: òkémọ́ẹ̀fà
7 èbie 7 With prefix: òkémọ́èbie
8 ẹ̀jọ 8 With prefix: òkémọ́ẹ̀jọ
9 ẹ̀lá 9 With prefix: òkémọ́ẹ̀lá
10 ẹ̀gwá 10 With prefix: òkémọ́ẹ̀gwá
11 ẹ̀gwáòkâ 10 + 1 With prefix: òkémọ́ẹ̀gwáǒkâ or ẹ̀gwányúòké is a possible alternative
12 ẹ̀gwáèjì 10 + 2 With prefix: òkémọ́ẹ̀gwáèjì or ẹ̀gwányúòkémọ́èjì is a possible alternative
19 ẹ̀gwáẹ̀lá 10 + 9 With prefix: òkémọ́ẹ̀gwáẹ̀lá or ẹ̀gwányúòkémọ́ẹ̀lá is a possible alternative
20 ógwú 20 Lexicalized base-20 form (cf. ọ̀gbọ̀)
21 ógwúnyúòké 20 + 1
22 ógwúnyúòkémọ́èjì 20 + 2
29 ógwúnyúòkémọ́ẹ̀lá 20 + 9
30 ógwúẹ̀gwá 20 + 10 ógwúnyúòkémọ́ẹ̀gwá is a possible alternative
40 ọ̀gbọ̀mọ́èjì 20 × 2
50 óje 50 Lexicalized base-50 form (cf. ólí)
60 ọ̀gbọ̀mọ́ẹ̀ta 20 × 3
70 ọ̀gbọ̀mọ́ẹ̀taẹ̀gwá (20 × 3) + 10
80 ọ̀gbọ̀mọ́ẹ̀lẹ̀ 20 × 4
90 ọ̀gbọ̀mọ́ẹ̀lẹ̀ẹ̀gwá (20 × 4) + 10
100 ọ̀gbọ̀mọ́ẹ̀lú/ ólímọ́èjì (20 × 5) / (50 × 2) Dual base strategy
200 ọ̀gwáọ́kọ́/ ọ̀gbọ̀mọ́ẹ̀gwá/ ólímọ́ẹ̀lẹ̀ (20 × 10) / (50 × 4) Multiple forms
300 ólímọ́ẹ̀fà 50 × 6
400 úluókó/ólímọ́ẹ̀jọ 400 / (50 × 8) Lexicalized and multiplicative
500 ólímọ́ẹ̀gwá 50 × 10
600 úlúọ́gwǎ / ólímọ́ẹ̀gwáèjì 400 + 200 / 50 × 12 Mixed strategy
700 ólímọ́ẹ̀gwáẹ̀lẹ̀ 50 × 14
800 íchámû / ólímọ́ẹ̀gwáẹ̀fà 800 / 50 × 16 Lexicalized and multiplicative
900 ólímọ́ẹ̀gwáẹ̀jọ 50 × 18
1,000 íchámûnyúọ̀gwáọ́kọ́ 800 + 200 Additive
1,001 íchámûnyúọ̀gwáọ́kọ́ nyúòké 1,000 + 1
1,010 íchámûnyúọ̀gwáọ́kọ́ nyú(òkémọ́)ẹ̀gwá 1,000 + 10
1,020 íchámûnyúọ̀gwáọ́kọ́ nyúógwú 1,000 + 20
1,100 íchámûnyúọ̀gwáọ́kọ́ nyúọ̀gbọ̀mọ́ẹ̀lú 1,000 + 100
1,200 íchámûnyúọ̀gwáọ́kọ́ nyúọ̀gwáọ́kọ́ 1,000 + 200
2,000 íchámûnyúọ̀gwáọ́kọ́ mọ́èjì 1,000 × 2 Multiplicative
10,000 íchámûnyúọ̀gwáọ́kọ́ mọ́ẹ̀gwá 1,000 × 10 Multiplicative
Download Excel Table

The Ígálâ numeral system follows a quasi-decimal pattern from 1–19, with values above 10 formed additively (e.g., ẹ̀gwáǒkâ ‘10 + 1’). From 20, it shifts to a vigesimal base (ọ̀gbọ̀mọ́èjì ‘20 × 2 = 40’), while a quinquagenary element (ólí ‘50’) introduces a hybrid vigesimal–quinary structure. Lexicalized forms for single units (ógwú ‘20,’ óje ‘50’) differ from the multiplicative bases (ọ̀gbọ̀ ‘20,’ ólí ‘50’), showing functional specialization; thus, 100 is expressed as ólímọ́èjì ‘50 × 2.’ Numerals beyond 1,000 extend recursively through addition and multiplication (e.g., íchámûnyúọ̀gwáọ́kọ́ ‘800 + 200’), reflecting structural economy and cultural arithmetic ingenuity.

3.1. Morphological Structure of Ígálâ Numeral

The Ígálâ numeral system comprises distinct lexical items for the numbers zero through ten, which serve as the foundational counting units as in (1).

Beyond these basic units, Ígálâ employs specialized lexical forms that serve as higher counting anchors as illustrated in (2).

These lexical bases form the backbone of the Ígálâ numeral system. The morpheme ọ́kọ́ “money, unit of value” grammaticalized from trade and commercial contexts into general counting, while úlú “four hundred” originates from agrarian usage, literally meaning “seed” and subsequently extended to countable large quantities. Higher numerals are then systematically constructed through functional morphemes that encode arithmetic operations, producing a fully productive number grammar as shown in (3).

The discussion in Sections 3.2–3.4 will therefore demonstrate how lexical anchors and grammatical operators interact to yield additive, multiplicative, and subtractive constructions, while further situating these processes within the broader dynamics of borrowing and contact that characterize the modern Ígálâ numeral system.

3.2. Addition in the Ígálâ Numeral System

Additive constructions in Ígálâ operate across three structural zones: (i) simple juxtaposition up to nineteen, (ii) templatic addition with ny(ú)òké(mọ́)/ny(ú)ọ́wọ́(mọ́) for units following higher bases, and (iii) free addition with nyú beyond nineteen.

3.2.1. Simple Juxtaposition (1–19)

Numerals from eleven to nineteen are formed by directly combining ẹ̀gwá ‘10’ with a unit. Alternatively, these values may also be expressed through templatic addition, reflecting the treatment of 1–9 as units within the quasi-decimal structure (4).

This direct juxtaposition is confined to the first cycle of addition but reappears in forms such as ógw(ú)ẹ̀gwá ‘30,’ where it functions as an idiomatic, lexicalized choice. By contrast, the templatic form ógwúny(ú)òkém(ọ́)ẹ̀gwá (‘20 + 10 units’) represents a more transparent, compositional strategy.

3.2.2. Templatic Addition for Units after Higher Bases

From twenty upward, additive constructions require the ny(ú)òké(mọ́) or ny(ú)ọ́wọ́(mọ́) template, the latter metaphorically invoking fingers as counting units. With ọ́wọ́ “one,” the morpheme mọ́ is omitted, giving ny(ú)òké or ny(ú)ọ́wọ́(ǒ)kâ, as shown in (5).

For numerals above one, the full template with mọ́ is obligatory, as illustrated in (6).

Thus, òké/ọ́wọ́ anchor lower numerals as atomic units, giving way to the bare additive nyú as the principal mechanism for constructing higher numbers.

3.2.3. Adding Beyond 19: Free nyú

For numerals above nineteen, only the bare additive nyú is grammatical, as extensions of the òké/ọ́wọ́ template produce ill-formed expressions as shown in (7).

Here, nyú alone sustains productive addition with higher bases.

3.3. Multiplication in the Ígálâ Numeral System

Multiplication in Ígálâ is expressed through the morpheme mọ́ “times” and by templatic strategies at various base thresholds. These strategies extend the system from single units up to billions and beyond. Multiplicative productivity is bounded at each base, reflecting both cognitive economy and cultural arithmetic conventions.

3.3.1. Multiplication in Base-1ː òkémọ́

At the lowest tier, multiplication is expressed by the template òkémọ́ X (‘1×X’), where òké “unit” functions as the immutable base and numerals 1–19 serve as multipliers. Within this range, mọ́ merely marks the pattern and signals the multiplicative structure without producing additional semantic content. Multiplication in Base-1 extends from 1 up to 19 and terminates; attempts to extend it to higher numerals (e.g., ẹ̀gwá mọ́ èjì = 10 × 2) are ungrammatical, illustrating the first structural ceiling in the system (Table 2).

Table 2. Base-1 Multiplication and Blocked Extensio
Expression Structure Status Notes
òkémọ́ èjì 1 × 2 Grammatical Base-1 multiplication allowed
òkémọ́ ẹ̀gwá 1 × 10 Grammatical Base-1 multiplication allowed
*òkémọ́ ógwú 1 × 20 Ungrammatical Base-1 multiplication blocked
*ẹ̀gwá mọ́ ẹ̀tá 10 × 3 Ungrammatical Base-10 multiplication blocked
Download Excel Table

This blocking principle motivates the shift to Base-20 (ọ̀gbọ̀) for higher numerals.

3.3.2. Higher Multiplication: Base-20 and Base-50 Templates

Beyond 19, larger numerals are constructed using Base-20 (ọ̀gbọ̀) and Base-50 (ólí) templates, supplemented by additive blends and lexical anchors. Base-20 multiplication (ọ̀gbọ̀mọ́ X) is productive up to 380 (20×19), the vigesimal optimum, which marks the structural ceiling of regular vigesimal computation. Additive constructions fill intermediate gaps, e.g., 30 = ógwú ẹ̀gwá, 70 = ọ̀gbọ̀mọ́ ẹ̀ta ẹ̀gwá.

Certain numerals are lexicalized: 50 = óje, 200 = ọ̀gwáọ́kọ, and 400 = úlúọ́kọ, with 200 also appearing transparently as ọ̀gbọ̀mọ́ẹ̀gwá (20 × 10). From 400 onward, Base-50 multiplication (ólímọ́ X) extends up to 950 (50 × 19), mirroring the vigesimal optimum, but it competes with vigesimal templates, additive blends, and lexical forms. Lexical forms dominate conventional usage, while templates provide arithmetically transparent alternatives (Table 3).

Table 3. Higher Numerals in Ígálâ: Base-20 and Base-50 Multiplication
Numeral Expression Structure Notes/Strategy/ Foreshadowing
50 óje Lexical form Quinquagenary innovation
100 ọ̀gbọ̀mọ́ ẹ̀lú / ólímọ́ èjì 20 × 5 /50 × 2 Alternative templatic forms; early Base-50 usage foreshadows vigesimal limits
200 ọ̀gwáọ́kọ / ólímọ́ ẹ̀lẹ̀ Lexical /50 × 4 Free variation; Base-50 mirrors vigesimal optimum
380 ọ̀gbọ̀mọ́ ẹ̀gwáẹ̀lá 20 × 19 Vigesimal optimum
400 úlúọ́kọ / ólímọ́ ẹ̀jọ̣ Lexical /50 × 8 Coexisting strategies; continues vigesimal ceiling analogy
600 úlúọ́gwǎ / ólímọ́ ẹ̀gwá ẹ̀jì Blended lexical /50 × 12 Lexical blend preferred; Base-50 templates transparent
800 íchámû / ólímọ́ ẹ̀gwá ẹ̀fà Lexical /50 × 16 Lexical anchor dominates
950 ólímọ́ ẹ̀gwá ẹ̀lá 50 × 19 Base-50 maximum; mirrors vigesimal ceiling
1,000 íchámû nyú ọ̀gwáọ́kọ 800 + 200 Additive composition; multiplication blocked
Download Excel Table
3.3.3. Multiplication at Higher Thresholds: Recursive and Juxtaposed Strategies

At the threshold of the thousands, Ígálâ reactivates explicit mọ́-based multiplication, which had receded in the mid-range cycles. For example, 2,000 is expressed as íchámû nyú ọ̀gwáọ́kọmọ́ èjì (1,000 × 2), and 19,000 as íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀gwáẹ̀lá (1,000 × 19). Here, the multiplicative marker mọ́ resumes its full arithmetic function, contrasting with lexical anchors and blends in mid-range numerals.

The vigesimal optimum continues to function as a structural ceiling in the Ígálâ numeral system, with mọ́-based multiplication productive only up to 19,000. Beyond this point, the system shifts from overt mọ́ marking to a strategy of juxtaposing free numerals and employing recursive compounding. For instance, 20,000 is expressed as íchámû nyú ọ̀gwáọ́kọ ógwú (1,000 × 20), while 1,000,000 is formed as íchámû nyú ọ̀gwáọ́kọ íchámû nyú ọ̀gwáọ́kọ (1,000 × 1,000), illustrating how higher numbers are systematically generated without extending the explicit multiplicative marker beyond the vigesimal threshold.

This recursive architecture allows indefinite extension: higher numerals are built by stacking lower anchors in strict descending order, with lexicalization, blending, and template strategies providing systematic, complementary mechanisms (Table 4).

Table 4. Higher Threshold Multiplication and Recursion in Ígálâ
Numeral Expression Structure Strategy/Notes
2,000 íchámû nyú ọ̀gwáọ́kọmọ́ èjì 1,000 × 2 mọ́-based multiplication (productive ≤ 19)
5,000 íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀lú 1,000 × 5 mọ́-based multiplication
10,000 íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀gwá 1,000 × 10 mọ́-based multiplication
19,000 íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀gwáẹ̀lá 1,000 × 19 Vigesimal ceiling reached; mọ́-based multiplication terminates
20,000 íchámû nyú ọ̀gwáọ́kọ ógwú 1,000 × 20 Shift to juxtaposition; multiplication marker blocked
50,000 íchámû nyú ọ̀gwáọ́kọ óje 1,000 × 50 Juxtaposition with lexical Base-50 anchor
100,000 íchámû nyú ọ̀gwáọ́kọ ólimọ́ èjì 1,000 × 100 (via 50 × 2) Juxtaposition of anchors; arithmetic transparent
1,000,000 íchámû nyú ọ̀gwáọ́kọ íchámû nyú ọ̀gwáọ́kọ 1,000 × 1,000 Recursive stacking of lower anchors
10,000,000 íchámû nyú ọ̀gwáọ́kọ íchámû nyú ọ̀gwáọ́kọ mọ́ẹ̀gwá (1,000 × 1,000) × 10 Recursion + localized mọ́ marking
1,000,000,000 íchámû nyú ọ̀gwáọ́kọ íchámû nyú ọ̀gwáọ́kọ íchámû nyú ọ̀gwáọ́kọ 1,000 × 1,000 × 1,000 Recursive compounding; no new lexical anchors
Download Excel Table
3.4. Subtraction in Ígálâ Numeral System

Building on the additive and multiplicative architecture, subtraction in Ígálâ is structurally simpler but functionally narrower, largely restricted to monetary and transactional contexts. The key marker is the morpheme chí “pluck,” which conceptualizes subtraction as the removal of a part from a whole. Its fixed syntactic template is:

Subtraction ensures clarity and structural transparency, as illustrated in (9).

Subtractive constructions are morphologically uniform and allow flexible combinations of minuends and subtrahends. However, they are cognitively more demanding than addition or multiplication, since the base must first be computed (e.g., 100 as 20×5) before subtraction is applied. Communicatively, the unpredictability of subtrahends further limits routine use.

Notably, subtraction does not conform to the vigesimal optimum (19) that governs productive multiplication. There is no ceiling on the size of either minuend or subtrahend; any higher numeral can be reduced by any smaller numeral. This contrasts with addition and multiplication, where the vigesimal optimum constrains productive combinations. Despite this, subtraction fully respects the hierarchical top-down ordering: the minuend (higher numeral) always precedes the subtrahend (lower numeral), consistent with the structural transparency of the Ígálâ numeral system.

Conceptually, the minuend precedes the subtrahend, in contrast to Latin-style ‘one from ten’ constructions, reflecting a distinct, transparent mapping of subtractive reasoning that aligns with the hierarchical and metrical architecture of the numeral system.

3.5. The Vigesimal Optimum as a Unifying Principle of the Ígálâ Numeral System

A defining feature of the Ígálâ numeral system is the vigesimal optimum (19), which sets a ceiling for productive multiplication across all arithmetic cycles. At the unit level, nineteen marks the upper limit of simple lexical items (ẹ̀gwáẹ̀lá = 19). In the vigesimal cycle, multiplication extends up to 20 × 19 = 380 (ọ̀gbọ̀mọ́ ẹ̀gwáẹ̀lá), while in the quinquagenary cycle, it reaches 50 × 19 = 950 (ólímọ́ẹ̀gwáẹ̀lá). In the thousands, mọ́-based multiplication operates from 1,000 × 2 up to 1,000 × 19 = 19,000 (íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀gwáẹ̀lá). Beyond this ceiling, multiplication via mọ́ is blocked, and higher numerals are expressed through nyú-mediated addition, lexical blends, or juxtaposition, as in 20,000 = íchámûnyúọ̀gwáọ́kọ ógwú or 1,000,000 = íchámûnyúọ̀gwáọ́kọ íchámûnyúọ̀gwáọ́kọ, illustrating recursive stacking of anchors.

While the vigesimal optimum governs multiplication, subtraction operates independently. Any higher numeral can serve as minuend or subtrahend without restriction by 19, highlighting that subtraction is a specialized operator rather than a fully integrated arithmetic cycle.

3.6. Hierarchical Ordering and Operator Architecture

This study confirms Comrie’s (2020) claim that Greenberg’s ordering universals should be treated as tendencies rather than absolutes. Crosslinguistically, languages such as Sakalava Malagasy and Insular Celtic show ordered shifts at structural cut-off points (e.g., 20, 60, 100), demonstrating that high-before-low ordering, though globally dominant, is not inviolable. Ígálâ, however, provides a counterweight within this spectrum: it exemplifies a strict descending system in which higher numerals consistently precede lower ones, without cut-off reversals or mixed strategies.

Grounded in the vigesimal optimum (19), Ígálâ organizes its numerals through a hierarchical template with dual operators: nyú marking additive or juxtaposed combinations and mọ́ marking multiplicative scaling. Additive forms like ẹ̀gwá(ǒ)kâ ‘11’ (10 + 1) contrast with the ungrammatical reversed ǒkâẹ̀gwá. Multiplicative constructions (ógwúẹ̀gwá ‘30’ = 20 + 10; úlúọ̀gwá ‘600’ = 400 + 200) maintain the descending order that Celtic systems, by contrast, relax after 20. Even subtraction (ọ̀gbọ̀m(ọ́)ẹ̀lú chí ẹ̀lú ‘95’ = (20 × 5) − 5) adheres to the same hierarchy, where Malagasy often permits alternative structuring.

Large numerals extend the same logic. Multiplication is capped by the vigesimal ceiling, after which juxtaposition applies, as in íchámû nyú ọ̀gwáọ́kọmọ́ ẹ̀gwáẹ̀lá ‘19,000’ (1,000 + 20 × 19) and íchámû nyú ọ̀gwáọ́kọ ógwú ‘21,000’ (1,000 + 20,000). The generalized Ígálâ template can be schematized as follows:

By maintaining recursive, transparent, and typologically coherent structures across all operations, Ígálâ buttresses Comrie’s crosslinguistic claim foreshadowed in Rutkowski (2003): even where universals admit exceptions, the high-before-low principle exerts strong gravitational force on numeral systems. Ígálâ thus provides a ‘purist’ case that sharpens our understanding of how robust tendencies manifest alongside controlled variability in the world’s numeral architectures.

3.7. Borrowing in the Ígálâ Numeral System

Borrowed numerals in Ígálâ reflect layered sociohistorical contact, including British colonial administration, Hausa trade, and contemporary English influence. These forms are functionally restricted, appearing almost exclusively in monetary contexts and rarely extending to general counting. From British currency, the term ípámû “pound” persisted well beyond Nigeria’s 1973 reform, with constructions like ípámû mọ́ ẹ̀lú (“pound times five” = ₦10) showing how colonial-era forms were arithmetically adapted to the naira. Hausa influence contributed èjìka (from jẹka, “bag”) for ₦200, especially in bulk trade (e.g., èjìka mọ́ ẹ̀gwá = ₦2,000). As Oyinloye (2020) notes, loanwords, a universal outcome of language contact, are not simple transfers but are reshaped by the structural preferences of the borrowing language. Beyond phonological accommodation, an Ígálâ calque àkpúlù “sack” appears alongside the Hausa form for “two hundred,” further illustrating this internal logic. More recently, English exerts pressure through code-switching, as urban youth increasingly use “two hundred naira” instead of indigenous èjìka (ǒ)kâ.

Such items exemplify Hammarström’s (2010) notion of a restricted numeral system: domain-specific, communicatively efficient, but structurally peripheral. While borrowed forms enhance clarity in monetary discourse, their spread threatens the integrity of Ígálâ’s indigenous numeral architecture. In this respect, Ígálâ resonates with broader typological concerns raised by Alphonce (2023) on the Cushitic languages Alagwa and Burunge, where Swahili contact has progressively displaced native numeral systems and curtailed intergenerational transmission. The difference lies in scale: whereas Alagwa and Burunge face wholesale replacement, Ígálâ demonstrates a reasonable containment strategy in which borrowed forms are integrated and functionally narrowed, though not without long-term risks.

4. Conclusion

This study has shown that the Ígálâ numeral system, though displaying a limited decimal arrangement in the lower range (‘one’ to ‘nineteen’), is best characterised as vigesimal. Counting in twenties is the generative base, with fifties reducible to twenties but not the reverse, confirming Omachonu’s (2011) analysis. Within this framework, Ígálâ exemplifies a strict high-before-low ordering: higher numerals consistently precede lower ones across addition, multiplication, subtraction, and large-number constructions. Through the dual operators nyú (additive juxtaposition) and mọ́ (multiplicative scaling), the system maintains recursive and transparent structures. In contrast to systems like Sakalava Malagasy and Insular Celtic, which show ordering reversals at cut-off points, Ígálâ stands as a ‘purist’ case of crosslinguistic tendencies, reinforcing Comrie’s (2020) view of Greenberg’s universals as strong but non-absolute principles.

Borrowed forms from trade and colonial contact exist, but they are peripheral and largely confined to monetary discourse, leaving the core architecture intact. This resilience underscores the adaptability of Ígálâ numerals in accommodating contact-induced items without compromising structural integrity. More broadly, Ígálâ contributes to typological debates by showing how robust ordering principles and vigesimal logic persist even in contact-rich settings. It thus offers a valuable test case for future comparative and diachronic research on numeral systems under conditions of variability and exchange.

Notes

§ This paper is a revised version of a paper presented at the 24th Annual Conference of the Linguistic Association of Nigeria (CLAN) held 5th-9th December 2011 at Bayero University, Kano, under the title ‘Preliminaries of Ígálâ Numeral System.’

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