Optional Agreement Patterns in Igbo

Apart from dominance and precedence relationship, other relations exist in syntactic constructions. One of such relations is the agreement relation. Scholars have discussed the clausal agreement relations of the subject and object. Many of such scholars working on Igbo grammar hold the opinion that Igbo verb forms do not inflect to mark agreement with their arguments. This study, which is purely descriptive without any theoretical colouration, describes and illustrates the optional agreement patterns in Igbo, with the intention to highlight the possibility of number agreement between Igbo verbs and their external and internal arguments. The study shows that clitic elements such as “cha/ga” and “nu” optionally attach to the verb in agreement with the plural subject or object in a sentence. Igbo verbs also take some extensional suffixes to agree with their arguments. We therefore gloss them as AGR morphemes.


Introduction
When we speak or write, we make genuine efforts to select appropriate words.In languages, words agree with others for intelligibility of sentences in discourse situations.In linguistics, meaning is attached to words and meaning derived from words in syntagmatic relationship is basically dependent on the agreement existing among them.In the Principles and Parameters Approach, agreement is assumed to be a universal element and different languages have different ways of marking it.It is also important to note that there are many languages that do not show any overt marker of agreement.Igbo seems to belong to that group.However, recent studies in Igbo have shown that Igbo operates a default agreement pattern (See Dechaine, 1993;Obiamalu, 2010).The present study attempts to investigate optional elements found on the verbs that signal agreement with the Igbo DP subjects.
The rest of the paper is divided as follows: Section 2 is the Literature Review which starts with the concept of agreement as a category in syntax and ends with the discussion of Agreement in Igbo.Section 3 presents and analyses the data.Section 4 is the summary and conclusion.

Literature Review
According to Trask (1993: p. 13), "agreement is a phenomenon by which appearance of one item in a sentence in a particular form requires a second item which is grammatically linked with it to appear in a particular form".Crystal (1985) postulates that traditionally, it refers to a formal relationship between elements, whereby the form of one requires a corresponding form of another to express person, gender, number etc. Asher (1994) says it is a relationship between a semantic or formal property of one element and a formal property of another.The above definitions imply that there is matching of features between two separate elements in a construction such that "B" agrees with "A" in "C".In other words, 'B' copies the number, person, gender, etc. features of the items in "A".Nzerem (2008: p. 1) exemplifies the matching features in the agreement relation as follows: if a sentence contains proper noun "Hilda" and later a pronoun "she", and they refer to the same person, we say that they agree in number (for both are singular) and gender (for both are feminine.The illustration above shows that the pronoun "she" (B) agrees with "A" (Hilda, the proper noun) in C (person and number).Tallerman (2005) observes that agreement occurs when the form of a syntactic constituent changes in order to agree with the form of other co-units within a linguistic domain such as a sentence, clause or phrase.In literature, agreement is synonymous with concord.Eka (2001: p. 181) puts forward three subtypes of concord in English-subject-verb concord, pronoun/antecedent concord and time reference concord.The subject-verb concord according to Quirk and Greenbaum (1973) is controlled by three principles.They are: Grammatical concord, Notional concord and the Principle of proximity.Vande-Guma et al. (2013: p. 103) says that the grammatical features which trigger grammatical agreement are reflected in linguistics as grammatical gender, person, number and case.Drawing attention to the subject-complement and subject-object concord, she gave the following instances.
1) a.The child was an angel.b.The children were angels.
2) a. John hurt his foot.b.John and Beatrice hurt their feet.Radford, Atkinson, Britain, Clahsen & Spencer (1999) identified lexical, functional and inflectional categories in syntactic constructions.The above authors observe that one of the three distinct categories is not an actual word, yet it (Infl) causes a change on the other two such that the "s" suffix though not a word but added to the lexical word "eat" marks tense and number agreement.According to Vande-Guma, Okebalama & Onukawa (2013: p. 98), agreement and other inflectional categories such as tense, mood, aspect and case reflect important syntactic functions in the formation of sentences and clauses.Pollock (1989) contend that INFL node which was formally analysed in GB as carrying the features of tense and AGR be divided into two functional heads-Tense and AGR phrases.One of the assumptions within the minimalist model hold that functional categories AGR and Tense contain case and phi features (number, person and gender) that may check off against features of their NP.Marantz (1995: p. 363) postulates that "the functional nodes AGR and T serve only to carry the morphological features of Ns and Vs".
The role played by verb morphology in showing agreement cannot be overlooked.Radford (1997) contends that agreement results when an inflectional morphology shows a syntactic relationship between the constituents of a sentence, clause or phrase.He observes that English, for instance, uses inflectional suffixes "-s", "es", "ren" etc. in constructions as in: 3) a.A boy came, b.Two boys came.4) a.She has a child b.She has two children.The above morphemes are bound to the verbs.In Tiv the subject-verb agreement obtains though not in all situations; the copula verbs "ngu (is) and mba (are)" inflect to mark number agreement with their respective subjects (Vande-Guma, Okebalama & Onukawa, 2013: p. 103).In Igbo language, verbs do not inflect for number agreement but may optionally cliticize with another type of bound morpheme different from inflectional suffixes which may check AGR features.According to Nweze (2009), the second category of bound morpheme is the clitic.Clitics are bound morphemes that are neither affixes nor words though they include contracted words.It is an item which appears intermediate between a word and an affix (Trask, 1993: p. 46).Clitics are named with regards to the position of occurrence such as proclitics, enclitics, endoclitics and mesoclitics.They serve to give additional meaning to sentences.When they function as mesoclitics and sometimes enclitics, they are part of the verb since they indicate "aspect and tense".They mark plurality and are used to reflect agreement in number.
Agreement relation in Igbo has in recent times become a subject of controversy among scholars working on Igbo grammar (Emenanjo, 1978;Manfredi, 1993;Mbah, 1999;Okeke, 2008;Uwalaka, 2003;Obiamalu, 2010;and Ikegwuonu, 2008).Some argue (Emenanjo, 1978;Manfredi, 1993) that Igbo has no tense agreement marker, aspect is the only functional category that is marked.Uwalaka (2003: p. 10) argues that Igbo does not permit the co-occurrence of an aspectual morpheme with tense morpheme.Obiamalu providing further evidence on Uwalaka's contribution says that "V" moves to aspect and since the aspectual morpheme and tense do not co-occur in Igbo, the V + Asp is blocked from movement to "T" so that the TP and AspP share the same head and occur under the same node.Okeke (2008) remarks that there is no gender agreement in Igbo; reflexives and their antecedent agree only in person and number.Mbah (1999Mbah ( , 2006) ) and Ikegwuonu (2008) observe that Igbo verb forms do not inflect to mark agreement with their external arguments; the Agreement features manifests only in Yes/No question involving the insertion of the pronominal copy of the NP immediately after the NP through the movement of the subject to the SPEC position.She (Ikegwuonu, 2008: p. 48) strongly advocates that the "notion of number agreement is only relevant to pronouns."Anyanwu (2007: pp. 93-94) contends that the complement clause verb covertly copies the tense properties of the matrix verb and notes as follows: The verb of the complement clause necessarily refers to a sub-part or aspect of a single over-all event.For this reason, the embedded verb acquires covertly the tense properties of the matrix verb.This means that tense, having been overtly marked on the matrix verb becomes a feature of the embedded verb; hence, it is redundant to mark it again.Obiamalu (2010) following Dechaine (1993) holds that Igbo has overt morphological agreement marker.They observe that E-prefix is a default AGR marker in negative perfective and past tense constructions.In the Igbo language, the investigation with respect to AGR relation remains open-ended as more researches reveal further findings on the subject matter.The present study investigates optional agreement patterns in Igbo constructions to show that some Igbo verbs can be formally marked to reflect the grammatical number of their external and internal arguments.In the present study, we investigate optional morphological markers of agreement in Igbo constructions.

The Data
The optional agreement markers could be classified into two types: clitics and extensional suffixes.Nweze and Ikegwuonu (2012) observe that the singular/plural phenomenon exists in Igbo though not as obtained in the Indo-European languages.One of the ways plurality is signalled is the use of the clitics.Consider the Igbo data in (5) below.5) a. Nwokē à nà-èzu ohī man DEM DUR-steal stealing "This man is a thief" b.Nwokē nà nwaànyị̀ à nà-èzu ohī Man and woman DEM DUR-steal stealing "This man and woman are thieves" c.Nwokē nà nwaànyị̀ à nà-èzu-cha ohī Man and woman DEM DUR-steal-CL stealing "This man and this woman are thieves" Notice that 5b & c have the same meaning.The coordinated nouns in 5b & c make them plural subjects.The presence of "chá" in 5c is therefore optional.Its absence does not rule out the grammaticality of the sentence as shown in 5b.One may argue that in 5b the agreement morpheme is suppressed (null).We shall therefore refer to the clitic "chá" in 5c as an agreement morpheme.It is ungrammatical to use "chá" with a singular subject as shown in 6. 6) a. *Nwokē à nà-èzu-cha ohī man DEM DUR-steal-CL stealing An interesting question to ask is why we refer to "cha" as a clitic rather than a verbal suffix?This is simply because "cha" is syntactically mobile.It can occur elsewhere other than after a verb.Consider 7 below (adapted from Emenanjo, 2015: p. 261) 7) a. Ndi à chà bìà-rà òriri PLU DEM CL come-rV feast "All these came to the feasting" b.Ndi à bìà-chà-rà òriri PLU DEM come-CL-rV feast "All these came to the feasting" c.Ndi à bìà-rà òriri cha PLU DEM come-rV feast CL "All these came to the feasting" It is interesting to note that "cha" can occur between the verb root and an inflectional suffix.This is evident by its occurrence before the inflectional rV Tense/Aspect morpheme in 7b.The fact that it can occur elsewhere as in 7a & c leads us to assume that "cha" in 7b is a clitic rather than an extensional suffix.It seems "cha" has no inherent tone.Its tone is determined by the tone of the peceding segment.The argument for clitichood is outside the scope of the present paper.(For details of the argument, see Anagbogu, 2001Anagbogu, , 2004;;Onukawa, 2001;Emenanjo, 2015) We present below more data from different forms of Igbo constructions to show that "cha" is an optional plural agreement marker.We shall henceforth gloss "cha" as AGR.
14) a. Ụlọ̀ m nà ǹkè gị bụ̀ ụlọ̀ ajā (cha) house 1S and PART 3S be house sand (AGR) "My house and your house are mud houses" b.Ji ndi à (chà) rè-rè ùre yam PL DEM (AGR) rot-rV rot "These yams are rotten" c.Àda nà Ǹkèchi lụ̀-bù-rù di (cha) Ada and Nkecki marry-PRIOR-FACT.PAST husband (AGR) "Ada and Nkechi were once married/Ada and Nkechi were married women" "cha" is an enclitic coming after the verb in 8c, 9b, 10b, 11b, 12b and 13b.It comes after the object NP in 7c, 14a and 14c.It appears after the subject NP in 7a and 14b.In all cases, it functions as a optional plural indicator in agreement with the plural subject of the sentence.
We present below, instances of 'nụ' functioning as agreement marker.16) a. Bìa ebe à come place DEM "Come here" b.Èmeka bìa ebe à Emeka come place DEM "Emeka come here" c.Èmeka nà Ibè bìa-(nụ̀) ebe à Emeka and Ibe come-(AGR) place DEM "Emeka and Ibe should come here" d.Kpèe-nụ̀ ikpe ahụ̀ ọ̀fụma judge-AGR case DEM well "Judge that case well" The clitic nụ is a second person plural marker which goes with imperative sentences.Since most imperative sentences do not have an overt subject as in 16a & d, the nụ clitic serves as the indicator as to whether the covert subject is singular or plural.In this case it is not optional.Notice that it is optional in 16c where the subject is overt.

Verbal Extensional Suffix "sị" as an Agreement Marker
Extensional suffixes are those that cast additional meaning to the roots to which they are affixed.In the words of Emenanjo (1978: p. 97) "the term extensional' is used in African linguistics for referring to elements, usually affixes, which function principally as meaning modifiers, that is, extending the meaning of the word with which they are used".Uchechukwu (2011) observes that they refer to the suffix components of the verb plus suffix structures with the suffixes expressing additional ideas.In otherwords, they are those elements that help to extend the meanings of the roots to which they are attached.Man DEM put-rVpast hand P pocket "The man put his hand into his pocket" b.Ụmụ̀ nwokē ahụ̀ mànyè-sì-rì aka n'àkpà PLU nwoke DEM put-AGR-rVpast hand P pocket "The men put their hands in their pockets" The interesting thing to note here is that the morpheme sị is the plural agreement morpheme which tells one whether the subject or object is singular or plural.In the absence of a plural modifying noun such as ụmụ, ndị, ọtutụ, it is si that tells us that either the subject or the object is a plural noun as in 20b.The point we are making here is that while the extensional suffix "si" could be used alone to mark plural, it is still in a way optional since the above sentences could be expressed without any overt plural agreement marker.This is illustrated in 22 below.

Summary and Conclusion
The study focuses on Igbo number agreement.The prompting of the study is the necessity to re-examine the postulation that Igbo verbs do not inflect to mark agreement with their arguments.It investigates optional agreement patterns in Igbo constructions to show that some Igbo verbs can be formally marked to reflect the grammatical number of both their external and internal arguments.
The work using different types of Igbo constructions, explored optional agreement pattern in the language.It discovers that the verb cliticizes with the morphemes "cha", "ga" and "nu" to form alternate elements that mark agreement with their external or internal arguments.Igbo verbs also take some extensional suffixessuch as "sị" to agree with their arguments.
In conclusion, Igbo language is very rich in its ability to produce options in varying syntactic constructions and relations.We therefore termed the constituents that mark number agreement between the subjects or the objects and the verbs as AGR morphemes.The nature of these optional AGR morphemes needs to be explained theoretically and we shall leave that for another study.
complete + together together chase all far insideThe examples in 17 show how extensional suffixes can modify or add more meanings to the verb root.Some of these extensional suffixes such as sị could be used in agreement with the subject or object NP.