A Lexical-Pragmatic Approach to Japanese Wakamono Kotoba ‘Youth Language’ yabai

This study uncovers the morphosyntactic properties of yabai and its clipped forms. It aims to arrive at an understanding of how the forms and the meanings might be associated. A lexical-pragmatic-based analysis was carried out using Twitter and speech corpus data. The findings reveal the following picture of the lexeme: (a) when yabai undertakes an adjective role, modifying a noun, it is likely that a negative evaluation is invited. In this regard, yabai fulfils a lexical function. (b) The adverb use of yabai presents two variations: modifying a verb or modifying an i-adjective. At any rate, the adverb use describes the degree of an event or an object, leading to the assumption that yabai fulfils a grammatical function. (c) The predicate function presents the following diversities: the negative-denotation yabai and yabee are lexical items; the positive/neutral-denotation yabai , yabee and yaba are grammatical items. The clipped forms, i.e. yaba ; yabee and yabe are limited to interjection use and adverb use, which are signs of complete grammaticalisation. A quantitative analysis via KH Coder suggests that yabai ’s adverb function appears to be limited to women friendships, with parent-child relationship and vertical relationship being ruled out.


Introduction
Language is constantly changing in meaning and in form (morphology). The extension of semantic meaning, and the derivation of parts of speech, are often tackled via: (a) a diachronic approach, treating the alternation as an outcome of grammaticalisation and lexicalisation (e.g. Traugott andHeine 1991, Givón 1971); or (b) a synchronic approach, addressing the shift from a cognitive semantic perspective. In this line of research, 'metaphor' and 'metonymy' are usually adopted to uncover the projection from the source domain to the targeted domain.
Japanese wakamono kotoba 'youth language' is a constantly altering linguistic phenomenon. It refers to phrases using words and expressions that are grammatically ill-formed but that are used and understood by young people. Extensive work has been devoted to this subject: see, for instance, the sociolinguistic approach, represented by Horiuchi (1989) and Hinoda (1998), or the psycholinguistic approach, represented by Ishihara et al. (2020). Theoretical accounts of wakamono kotoba do not appear to have been exhaustively set out, except for two case studies: (a) Seraku and Akiha (2019), who apply the notion 'attenuation' (Segerer and Treis, 2018) to address the innovations of Japanese poi; and (b) Seraku's (2020) discussion of the properties of the Japanese nominalising suffix -mi in the framework of nominalisation proposed by Masayoshi Shibatani.
The present study is devoted to another case study: the Japanese i-adjective (Note 1) yabai ('risky'). The study investigates its morphosyntactic properties and semantic meanings, based on a speech corpus and Twitter data. With this in place, it aims to arrive at an understanding of how forms and meanings are associated.
The point of departure for this study is the fact that yabai has changed a lot since earlier times. Originally, it was a noun, i.e. 厄場 yaba 'prison'. During the Edo Period (1603-1868), the noun 厄場 morphed into a na-adjective and was written in kana 'やば'. Since then, yabana has been registered as a na-adjective in all dictionaries. Below is an illustration from a Kokkeibon: Tookaidoochuu Hizakurige (1802-1809).
'You, do not do risky things!' [Tookaidoochuu Hizakurige: 1802-1809 It was in the early Showa Period that the na-adjective yabana shifted into being an i-adjective and morphologically altered, becoming the form yabai. An illustration is provided in (2).
(2) I-adjective ( (Asakusa Kurenaidan (1929-1930 It also ought to be noted that in the Early Showa Period, yabai conveyed only a negative reading. Until the Heisei Period (1989-2019) yabai was officially listed as an i-adjective in dictionaries, conveying a positive sense and yielding new parts of speech (e.g. adverb, interjection). These syntactic and semantic variations are exemplified by (3)-(8).

(I) Adjective
The adjective yabai plays two roles: as a predicate (3) and modifying a noun (4).
(3) Taroo no keekaku wa yabai. Bear in mind that the predicate use of yabai may denote a positive meaning 'marvellous' or a negative meaning 'bad'. The interpretation relies entirely on the context.
Dem bag TOP very expensive 'This bag is extremely expensive.' In fact, the combination of two i-adjectives in finite form is ruled out in standard Japanese, but it occurs quite often.
(6) Adverb yabai modifies a na-adjective At this stage, we can pause and draw a map of yabai's shifts in morphosyntax and phonology. International Journal of Linguistics ISSN 1948-5425 2021 www.macrothink.org/ijl 5 Figure 1. Yabai's morphosyntactic and phonological shift Among the various functions that yabai conveys, the adjective use, which modifies a noun, is likely to render a negative reading. This inspires us to ponder whether perhaps the syntactic category is linked with semantic meaning: such as that the adjective function is likely to convey a negative sense whilst the adverb function invites a positive reading. To this end, we carry out a lexical-pragmatic approach, examining the morphosyntactic properties and the evaluations that yabai denotes.

The combination of yabai + other parts of speech
The database for this research consists of corpus data and posts from Japanese Twitter: the Corpus of Everyday Japanese Conversation (CEJC, provided by the National Institute of Japanese Language and Linguistics). NINJAL-LWP (provided by the National Institute of Japanese Language and Linguistics and the Lago Language Institute) is employed for the frequency investigation. It should be noted that there were 148 instances of yabai in the CEJC, and the Twitter data was accessed on 14 December 2020. Since the central goal of this paper resides in the innovated use of yabai, it is thus the very data of the predicate, interjection and adverb use that will be delved into in depth.
The paper is organised as follows. Section 1 has set the stage for what follows by giving a brief introduction to the multiple functions and meanings of yabai. Section 2 provides an insight into the previous work that has tackled yabai in the past: a descriptive account and a theoretical account. Building on this, it proposes a generalisation to yabai's various characteristics. Section 3 analyses the morphosyntactic derivation, as well as semantic extension based on corpus and Twitter data. Section 4 turns to the functions and meanings in the clipped forms: yaba; yabee and yabe. Section 5 highlights the results and addresses the theoretical implications of this study.

Previous Studies
This section draws on previous work that has tackled the word yabai in the past, investigating descriptive work and theoretical studies. Building on this, a hypothesis is put forward to generalise the diverse functions and meanings of yabai and its clipped forms. The descriptive work on yabai mostly departs from a sociolinguistic perspective. Sano (2012) and Horasawa and Iwata (2009) conduct an investigation of 3,000 people over 16 years old across the country and calculate the frequency of using 'youth language'. Kumagai (2014) looks into the acceptance of yabai among different generations, ethnicities and genders. The descriptive work has well addressed the character of yabai and its use among different generations. Yet a theoretical account of the morphosyntactic properties of yabai remains unattempted.
Different studies have been undertaken at the theoretical level, tackling a variety of phenomena. Cognitive semanticians suggest that yabai's semantic extensions are facilitated at a conceptual level. This comprises a metonymic approach to the relationship between the source and the target domain (i.e. cause/effect, part/whole, possessor/possessed), e.g. Voßagen (1999); Sakaguchi (2013). Another pathway is that taken by Takeuchi (2007), who applies a cognitive-pragmatic approach, adopting the framework of 'relevance theory' (Sperber and Wilson l995) (Note 2) to address the double-interpretation conveyed by yabai's adjective function.
Cognitive semantics is helpful in that it accounts for the semantic extension, which is grounded in metonymic operations. However, the following phenomena are not accounted: the interjection and adverb uses of yabai, and the clipping. Therefore, the cognitive approach might not help us to arrive at a unified understanding to the multiple faces of yabai as it pays too little attention to the syntactic functions, and to the link between form and meaning. This study, identifies the following classes: (10) A generalisation to utilise the diverse parts of speech and meanings in yabai The various functions and semantic readings that yabai provides in Modern Japanese fall into two strands.
a. The adjective, predicate use of yabai fulfills a lexical function.
b. The adverb and interjection use of yabai fulfil a grammatical function (Note 3). ISSN 1948-5425 2021 www.macrothink.org/ijl 7 To further support this position, an analysis is carried out in the following section.

Yabai's Morphosyntactic Functions and Semantic Meanings
Our starting point is yabai. This study randomly drew 60 tokens of yabai from CEJC and calculated the frequencies, the meanings that each category conveys in light of KH Coder (produced by Kooichi 2017). KH Coder analysis brough us to the point that the 1 st lexeme on the right side of yabai attributes the most tokens, which in turn suggests that yabai is more likely to modify an adjective or a verb, fulfilling the duty of an adverb.
The following presents a closer picture: the most common option in terms of yabai is the interjection use (29 tokens). The predicate function is equally common, accounting for 27 tokens. Four tokens apply to the adverb use.  ISSN 1948-5425 2021 www.macrothink.org/ijl 8 Having examined this data, we are now in the position to analyse yabai's morphosyntactic functions and semantic meanings.

Interjection yabai
As suggested by Table 2, a common option for yabai is to fulfil the interjection function. This is illustrated by the examples in (11). (11)  At this stage, it can be suggested that the interjection function appears to be a kuchiguse 'habit of saying' and, crucially, such a habit of saying can vary from individual to individual. This would suggest that the interjection function of yabai fulfills a grammatical function.

Predicate yabai
The second largest token number among yabai come from the adjective function, which may render a predicate or modify a noun. A search in NINJAL-LWP shows that among the 245 tokens (73 types) of yabai's modifying a noun, all tokens appear to convey a negative reading. This having been said, the following Twitter data presents a different picture: yabai renders a positive reading. Yabai describes the size of the scale of the event. The noun that it modifies is a Sino-Japanese word: daikiboo 'big scale', where there is already a modifier, i.e. dai 'big'. This inspires us to deduce that yabai is modifying a modifier and ought to be deemed as an adverb. One may argue that dai is not an independent word but a prefix, attached to the noun kiboo 'scale', and thus daikiboo ought to be deemed a noun. Pulling these strands together, we cannot but contend that yabai is fulfilling the adverb function and ought to be considered as a grammatical item.
Such data is only detected once. The other data of [yabai + noun] all convey a negative evaluation. It is thus to the predicate function that we will now turn.
As suggested by A salient property of this yabai is that it has an original meaning: it describes the consequence of missing a flight, i.e. bad. With this in place, yabai here has a lexical function.
The following example is another illustration of the predicate use, presenting a different picture. Building on the context, we assume that yabai here renders a positive reading. This piece of data leads us to assume that yabai here fulfils a grammatical function.

Adverb yabai
The grammatical function seems to be further tied to the adverb use of yabai. Consider the following data. The data from the CEJC suggests that, when yabai modifies an adjective, it is likely that the adjective itself renders a positive reading. Thus, the whole expression is positive. The following data is drawn from Twitter, where yabai is followed by an adjective that yields a neutral reading.
Outside ADV cold 'It is extremely cold outside' [Twitter 8/Dec/2020] The above data indicates that when yabai modifies an adjective, it does not carry any evaluation but merely describes the degree of the following adjective. Building on this, we contend that the adverb yabai fulfils a grammatical function.
Additional intriguing data is noted, i.e. [yaba + dative case particle ni]:  ISSN 1948-5425 2021 www.macrothink.org/ijl 11 'As for the company ONLY, the scale of (this event) is very big. It turns out to be a very big scale.' [Twitter 29/Nov/2020] It is important to notice that the first appearance of yabai modifies a noun, cf. yabai daikibo ni nattete. It is the second yabai that we are concentrating on, which is followed by the dative case particle ni, cf. yabai ni natteru. This expression yields a positive reading, i.e. how big the event is. The construction [yabai + dative particle ni] suggests that yabai is either a noun or a na-adjective. Or, alternatively, perhaps an ellipsis is involved in this yabai. In the database, such an expression is only detected once. With this being the case, it is not appropriate to contend that yabai displays a noun or a na-adjective function.

The Clipped yabai
Having drawn a picture of yabai conveying an interjection, an adverb and a predicate, this section presents a further picture: three clipped forms of yabai, i.e. yaba; yabee and yabe. To provide an adequate account of the morphosyntactic properties and the semantic meanings of the clipped yabai, this study took 81 tokens from Twitter at random and calculated the distribution of their functions. Most tokens of yaba and yabe come from the interjection use, which leads us to deduce that yaba and yabe may have lost their original function, i.e. as an adjective, modifying a noun. It was also discovered that yabee bears four parts of speech, with the adjective as the main function and the predicate use as the second.

Yabee
The multiple morphosyntactic properties of the clipped yabai are particularly pronounced in the form yabee. Apart from the basic function, i.e. an adjective, modifying a noun (1), four innovations are observed: na-adjective; adverb, predicate and interjection. Among them, the na-adjective function is particularly worth commenting on. ISSN 1948-5425 2021 The data in (1), however, differs from the one centuries ago: yabee, as a na-adjective nowadays, is an adverb, modifying a VP. To put it another way, although yabee appears to be a na-adjective, it actually modifies a VP. Here, it refers to 'badly'. Thus, the nuance of yabee na owa toru turns out to be: 'the ending is badly taken'.

Predicate yabee
Turning to yabee's predicate function, a common function of yabee is to render a negative meaning. An illustration is provided in (25).
(25) Predicate yabee (negative reading) [On a snowy night, the writer posts a photo of a car, which is fully covered by snow. The writer says: by tomorrow, the car would be a disaster!] This leads us to the observation that the predicate yabee, when yielding a neutral or a positive reading, is fulfilling a grammatical function. ISSN 1948-5425 2021 www.macrothink.org/ijl 14

Interjection yabee
The interjection use of yabee is represented by (28) Having all this in mind, we can say I. When yabee behaves as an adjective, its fundamental role is to modify a noun with a negative evaluation, and thus we deduce that the adjective yabee is a lexical item.
II. The na-adjective function of yabee is an innovation. It should be borne in mind that although yabee appears to be a na-adjective, it actually modifies a VP, and thus ought to be deemed as an adverb, fulfilling a grammatical function.
III. The adverb use of yabee presents two variations: modifying a verb or modifying an i-adjective. At any rate, the adverb use renders a degree of the event and is deemed to be a grammatical item.
IV. The predicate function presents the following diversities: the negative-denotation yabee is a lexical item; the positive/neutral-denotation yabee fulfills a grammatical function.
V. In addition, when yabee renders an interjection function, it is a grammatical item.

Yaba
It is the second clipped form, i.e. yaba, to which we now proceed. A typical example of the interjection use would be (29) The predicate use is also seen. ISSN 1948-5425 2021 Incorporating these observations, we deduce that the original meaning is retained in the function of a predicate, which in turns indicates it as a lexical item. The interjection, adverb, and the positive predicate use of yaba, contribute a grammatical function.

International Journal of Linguistics
So far, the multifaceted functions and meanings of yabee and yaba have been analysed. There is one remaining issue, i.e. the third clipped form yabe. It is not as favoured as yabee or yabai.
In the randomly collected database, only ten tokens are detected, seven out of which render an interjection use. One token applies to the basic function and meaning, one token is attributed to a negative reading, as a predicate, and one is attributed to a positive reading, as a predicate. These diversities indicate that yabe is also a two-faced lexeme, fulfilling a grammatical function, on the one hand, and functional a lexical function on the other.

Summary
Based on the morphological, syntactic and semantic evidence given above, that the diverse parts of speech and semantic meanings split into two categories: (a) a grammatical function is applied to the interjection, positive/neutral-denotation predicate, adverb and na-adjective functions; and (b) a lexical function is fulfilled by a negative-denotation predicate and adjective that modifies a noun.
A further look at the cooccurrence network of yabai via KH Coder (cf. Figure 3) reveals that, a. yabai is mostly likely to cooccur with adjectives, where yabai fulfils an adverb duty.
b. yabai's adverb function is mostly seen in conversations among women friends than official conversations in company or government.
c. yabai's adverb function appears to be limited to friendships and is ruled out by parent-child and vertical relationships. ISSN 1948-5425 2021 www.macrothink.org/ijl 16 Figure 3. The cooccurrence network in regard to yabai

Concluding Remarks
Modern Japanese has a quite developed wakamono kotoba 'youth lexicon', e.g. the suffixes -mi, -poi, -sugiru, -kusai have established syntactic functions and semantic meanings that are different from standard Japanese. The study of yabai is of particular interest in the study of lexical pragmatics because, apart from its meaning being extended, it appears to have innovated an adverb use and an interjection function. The main goal of this study was to uncover the morphosyntactic properties of yabai and its clipped forms. It aimed to arrive at an understanding of how the forms and the meanings might be associated. A lexical-pragmatic-based analysis, based on Twitter and corpus data, was carried out. The finding yield the following picture of the lexeme. I. When yabai and yabee undertake an adjective role, modifying a noun, it is likely that a negative evaluation is invited. In this regard, yabai and yabee fulfil a lexical function.
II. The adverb uses of yabai and yabee presents two variations: modifying a verb or modifying an i-adjective. At any rate, the adverb use describes the degree of an event or an object. Incorporating this, the adverbs yabai and yabee fulfil a grammatical function.
III. The predicate function presents the following diversities: the negative-denotation yabai and yabee are lexical items; the positive/neutral-denotation yabai, yabee and yaba are grammatical items.
Yabai awaits further research, i.e. driven by cognitive semantics delving into the extension process; a diachronic study, searching for the evolution path at different historical stages. The interjection, adverb use of yabai is probably down to grammaticalisation. The clipped forms, i.e. yaba; yabee and yabe, as Table 3 suggests, no longer render an adjective function. Their functions are limited to interjection use and adverb use. The completely lost original part of speech, and the morphophonological change (i.e. clipping), are signs of complete grammaticalisation. In terms of yabee, it does not seem to have reached the end of grammaticalisation, as there are still tokens indicating a negative evaluation as an i-adjective. The positive and neutral readings of the predicate yabai and yabee have to do with semantic extension.
It is clear that there is much work to do in this field, but nevertheless we hope this work has provided a sound base for further research.  ISSN 1948-5425 2021 www.macrothink.org/ijl