Floating Tone in E ̀ su ̀ ku ̀

Abstract


I. Introduction
Esukù is one of the speech forms of Abesabesì spoken in a small quarter also known as Esukù within Ajowa community in Akoḱó North West local Government area of Oǹdó State Agoyi (2003).According to Elugbè (2011), Esukù belongs to Akpes; a sub-group of Akedoid (Akoḱó plus Edoid) branch of Edoid language family.Agoýì (2008) claims that Akpes is spoken in nine Akoḱó communities of Oǹdó State which are mutually intelligible.The communities are: Akuǹnu, Akuǹnù (iludotun), ikaŕamu, ibaŕamu, Àse, Iỳiǹi, Gedegede, Daja and Esuku.Apart from Akuǹnù which is in Akoḱó North East local Government; all the other communities are located in Akoḱó North west local Government area of Oǹdó State.
Esukù is situated within the linguistic sphere of one of the major languages in Nigeria, and based on our findings in the course of this research work, we reveal that, speakers of the Esukù speak Yoruba̒ more often than their native speech form.Apart from this, its domain of use is restricted to their homes.For instance, during Olili festival (a ceremony of the virgins), the language of conversation is Yorubá rather than their speech form according to one of our informants.Esukù is not codified, thus there are no written literatures.Also, the younger ones in this speech community can no longer speak Esukù without inter-sentential code-mixing.All these suggest that this speech form is seriously endangered.
The motivation for this research is hinged on two reasons; first is the fact that, a detailed works on the phonology of the Esukù is yet be carried out.The present paper is therefore an effort to fill the gap by looking at an aspect of the phonology of the speech form.Specifically, the paper describes the nature and function of floating tone in Esuku.Secondly, this work is an attempt to document Esukù bearing in mind that the speech form is seriously endangered.
This paper is divided into four sections.Section one is the introductory section of the paper, section two discusses the theoretical framework adopted for this work.Section three presents the main focus of the work which is floating tone in Esukù while section four is the concluding part of the paper.

Theoretical Framework
Autosegmental theory of phonology proposes that tone and segments should be treated separately.i.e. as autonomous entities.This theory is preferred because despite the ability of the Generative Phonology to handle some phonological issues, the theory is said to focus on segments only.Autosegmental phonology which was formally developed by Goldsmith (1976) posits that tonal and segmental tiers (consonants and vowels) should be accounted for at different levels of representation.This theory adequately captures our analysis of floating tone in this paper.The principles and orientation of this theory are well discussed in Goldsmith (1976a, b), Clements (1974, 1976, and 1977), Durand (1990), Kenstowitz (1994), Corbett (1998), etc.Since autosegmental theory allows for independent levels, one of the basic issues addressed by the theory is the synchronization of levels.The different levels must be associated for the purpose of co-articulation.The linking process is normally subject to a set of well-formedness condition (WFC) that are presented below: 1. Link autosegmental bearing unit left-right or right-to-left one-to-one, 2. Link leftover autosegment bearing unit with the last autosegment bearing unit, 3. Link leftover autosegment to the last autosegment bearing unit, 4. Association lines do not cross.(See Durand, 1990:249) The above Well-Formedness Condition (WFC) is illustrated using tone as shown below: Whereas (1a-c) are well formed, (1d) violates the WFC and should not be allowed in derivations because it violates the principle 4 of the WFC.Durand (1990:251) says that association or linking can only go from left to right.This claim seems to be limited because pieces of evidence from natural languages in the areas of vowel harmony and tone copying have shown that association or linking may also go from right to left.For instance, in a language where prefixes and suffixes harmonize with root, the association is always bi-directional, e.g.

+ATR
CV + CV CV + CV Similarly, where an inherent toneless element occurs to the right or left of a root form, linking in form of spreading can be from right to left, e.g.

3.
H L V + CV CV + CV However, Autosegmental theory will be adopted because of its problem-solving advantage over Generative phonology especially in the areas of tone, vowel harmony, and nasality.(cf Goldsmith 1976a, b, Clements 1974, 1976, 1977, Durand 1990, Kenstowicz 1994, and Corbett 1998, etc.).Issues such as feature-stability, tone melody, floating tone, tone copying that have proved difficult to explain within the Generative Phonology are hitherto captured easily and accounted for within the nonlinear theory.Goldsmith (1976:45) notes that 'floating tones' constitute "…a device that has proven useful in working with tone languages but whose theoretical status has always been suspect".In a linear framework, it is to be expected that as tones are regarded as part of the feature bundle of the vowel.Goldsmith goes on further to define a floating tone as "…a segment specified only for tone which, at some point during the derivation, merges with some vowel, thus passing on its tonal specifications to that vowel."As Goldsmith point out, this is the traditional view of a floating tone.Also, Abióduń (2005) says that "in some cases in tone languages, some morphemes do not consist of segments; rather they are represented by tone at the underlying level.Such tones that do not have overt tone bearing segments are referred to as floating tones.A floating tone may eventually be associated to a segment at the surface level, it may be left floating, or it may change the status of a tone in its vicinity."Scholars that include Akinlabi (1986) among others have discovered two types of floating tones, namely: the phonological floating tone which is always as the result of the deletion of the tone bearing unit (TBU), and in most cases, it realigns with the neigbouring segment to form a contour tone which later simplifies to a level tone.The second type of floating tone is the morphological floating tone which is equal to a morpheme.This is the case obtainable in the genitive nouns and between a noun and a verb that follows it in a declarative sentence that we have discussed in this research paper.

Previous Works on Floating Tone
Floating tones are manifested in several tone languages.It is reported in Yoruba, Igbo, Tiv, Efik, among others Abióduń (2007).For instance, Baḿgboṣ́ é (1966), Awobuluýì (1988), andOyelaŕaǹ (1974) among others have discussed the presence of a floating high tone between a noun and a verb that follows it in a declarative sentence in the Yoruba language: Note that ojò 'rain' and ayọ 'personal name' in (4) carry L-L and M-L at the underlying level respectively, but at the surface level they come up with L-H tone.In normal speech, the floating high tone aligns with the final vowel of the noun to form a contour tone which later simplifies to a leveled high tone.

5.
ojó rọ ̀ Note that ojò 'rain' carries L-L at the underlying level, but at the surface level it comes up with an L-H tone.The floating tone is responsible for the change in the tone of the final vowel of the noun subject.Also, Ọ ladejì (2014) says that, "this process of floating tone aligning with the final vowel of the noun, and the underlying tone of vowel getting delinked also occurs in the North-East Yoruba".Consider the following forms:
The presentation above shows that, Ọ ladejì (2014) authenticates the claims of Baḿgboṣ́ é (1966), Awobuluýì (1988), and Oyelaŕaǹ (1974).However, Shada (1988) reports that in some dialects of Yoruba like the Ilaje and Ikale tone does not float.What obtains in these dialects is that a vowel that carries a high tone normally occurs between the noun and the following verb as shown below:

7.
ojò ó rọ ̀ nanaà́ 'it rained yesterday/Rain fell yesterday' ẹ fọ n ó jẹ ọ mọ naá̀ 'Mosquito bit the chid' ayọ ̀ ó suǹ 'Ayọ ̀ slept ' Shada (1988) calls this item /o/ a recapitulatory pronoun, which refers to the subject of the sentence.Awobuluýì (1988) however considers the item a preverbal element that marks completed action as the floating.We agree with Awobuluyi in this regard because the element does not refer to the subject.We make reference to Ilajẹ and Ikalẹ ́ to show that Esukù differs from some dialects of Yorubá but similar to the standard dialect in the aspect of a floating high tone between a noun and a verb that follows it in a declarative sentence in that, the floating high tone that marks completed action has no tone bearing unit (TBU), i.e, it is represented by a tone (floating high tone).
Furthermore, Oyebadé (1998) notes that Igbo has been commonly identified as operating (a) floating tone as the associative morpheme; this is evident from the phrase below:

8.
agbà eǹwè agbá eǹwè 'monkey's jaw' jaw monkey Notice that an extraneous high tone which is neither underlying to the morpheme for 'jaw' nor to the morpheme for 'monkey' surfaces in noun-noun constructions.It has been suggested by Williams (1971), Goldsmith (1976), among others, that this high tone is a segmentless morpheme acting as a genitive marker.Having examined the manifestation of floating tone in the works of the scholars above, the remaining part of the study will be dedicated to the discussion of floating tone in Esuku.

Floating Tone in Esukù
Esukù shows evidence of a floating high tone in noun-noun constructions (genitive construction) and declarative sentence( between NP and VP).The presentations below show how they manifest.

a. Floating Tone in Genitive Nouns in Esukù
There are two types of genitive markers in Esuku.The first type is marked by [ọ ni] which is usually prefixed to the root words which are normally nouns rather than verbs as shown below:

9.
ọ ní + oyo ọ noýo 'dancer ' ọ ní + iṣ o ọ niʃo 'owner of a house' ọ ní + ẹ nami ọ nɛńami 'owner of/dealer in meat' ọ ní + ọ hunẹ ọ nọ hunẹ owner of tree/dealer in tree' However in this paper, the interest is on a floating tone as a genitive marker, hence discussions on the oni-as a genitive marker in Esuku will be reserved for future research.Genitive in a noun-noun construction is usually marked by a floating high tone that occurs between the nouns.The examples below show how the floating tone manifests in the language.

10.
i A cursory look at the presentation above shows that final vowels of the first noun (N1) in V1 # V2 environment carry mid (i, ii, iii, iv, v, vi, vii, ix, x) and low tone (viii) at the underlying level, but at the surface level they come up with a high tone.We illustrate the derivation with the autosegmental schema below: Looking at the data above, we observe that ɛbiŋi "drum" carries M-M-M at the underlying level, but at the surface level it comes up with a M-M-H pattern; the underlying tone of V1 gets delinked after the realignment of a floating high tone.Apart from the floating high tone alignment with V1 in V1#V2 environment as shown in the schema above (11), we also observe a case of V2 elision in V1#V2 environment with its tone as shown below: 12.
i Going through the data in ( 12), we observe that, V2 (with its tone) is normally deleted while V1 survives the elision process in V1#V2 environment.We illustrate the derivation with the autosegmental schema below: Ø From the foregoing we could deduce that, cases where we have V1#V2 pattern, V2 is normally deleted while V1 usually survives the elision process; thus, the elision of V2 in V1#V2 environment is predictable since it is consistent throughout the data in (10).But there are cases in (10) where N2 (second noun) begins with a consonant segment as shown below: 14.
i Looking at the data above, we observe that "iṣ o" carries M-M at the underlying level, but at the surface level it comes up with a M-H tone; the underlying high tone on the final vowel of N1 gets delinked after the realignment of a floating high tone in V#C environment.This may make a casual observer to assume that tone alignment takes place before the elision process in data 11 since we have patterns where elision process is not applicable as a result of the nature of the structure as shown in data 14.However, this kind of assumption may not be correct when one considers the consonant initial nouns (Tití Tọ ṕẹ ́ and Jide) in 14.This observation may be likened to what obtains in Yoruba language.With regards to the Yoruba language, Awobuluyi (2013) argues that the vowel that exists between two nouns where the second one begins with a consonant in a Yorubá noun phrase like; Note that ẹ nami 'animal/meat' carries M-M-M, ẹ pa L-M, eyi M-M and Obami M-M-M , at the underlying level, but at the surface level they come up with M-M-H, L-H, M-H and M-M-H tone respectively.The floating high tone is responsible for the change in the tone on the final vowel of the noun subject.We illustrate the derivation with the autosegmental schemas below:

M H M M H M M H M M H M
e y i # y el i e y i y el i e y i yel i e y i ye l i eyí yeli Looking at the schema above, we observe that eyi "rain" carries M-M at the underlying level, but at the surface level it comes up with a M-H tone.The floating high tone aligns with the final vowel of the noun to form a contour which later simplifies to a level tone, and the tone of the vSSowel delinks.

IV. Conclusion
In this paper, it has been establish that Esuku has a floating high tone as a genitive marker in a noun-noun construction apart from the prefix genitive marker /ọ ni-/ and the presence of a floating high tone [] between a noun and a verb that follows it in a declarative sentence.It has been argue that, a floating high tone aligns with the final vowel of the first noun (N1), and the underlying tone of the vowel gets delinked in noun-noun construction and also, between a noun subject and the verb that follow it.Note that the floating high tone between NP and VP in declarative sentence in Esuku signifies a completed action.
The[i]prothesis normally undergoes a perseverative assimilation such that it becomes like the final vowel of the first noun as seen in (16).He further asserts that all nouns in Yorubá are vowel-initial.This is probably applicable to Esuku.Hence it may not be misleading to suggest that Esuku nouns are vowel initials.In this respect, we represent the underlying forms of the data in 14 as; Base on 17 above, we can therefore argue that, elision of V2 takes place before tone realignment; in V1#V2 environment V2 gets deleted with its tone and the floating high tone forms a contour tone on the neigbouring vowel which later simplifies to a leveled high tone because Esukù does not permit two contiguous vowels across morpheme boundaries, therefore, V2 has to be deleted and as a result of this, the floating high tone realigns with the neighboring segment.We illustrate the derivation with the autosegmental schema below: