Introduction

Researchers have been interested in the question of when different mood and modal elements are acquired in early childhood in different languages. This interest has stimulated discussion of theoretical issues regarding pragmatic, semantic and syntactic processes in different developmental stages of child language. This chapter is mainly concerned with how early mood/modal elements, along with temporal/aspectual and other functional elements, are acquired in Korean. Other related investigations include S. Choi's (1995) study of epistemic modals in cognitive development and H. Han's research (in this volume) on functional categories in generative grammar.

All inflectional elements, including modals, are acquired rather late – after 2 years of age – in Indo-European languages including English (Radford, 1990). However, in the acquisition of Korean, a verb-final language, sentential endings encoding a variety of moods, sentence types, modal differences, and even politeness are acquired much earlier. This study will investigate in what order these mood/modality indicators are acquired and what aspects of cognitive and linguistic development the data illuminate. Whether functional categories or projections, as elements of universal grammar, can be found in child grammar is also an interesting theoretical question to consider.

This study is based on my longitudinal diary notes on my own children (SK=Suh-Kyung, daughter, and CK=Choon-Kyu, son) from the babbling stage to over 10 years of age. These notes will be regularly compared with diary notes from a female child relative (YJ=Yoon-Jung) and an additional male child (H=Hyuki, a colleague's son) for tense/aspect.

The basics of Korean

This chapter briefly introduces some characteristics of the Korean language and its writing system and gives an overview of the chapters treated in this volume on Korean psycholinguistics.

Korean has the eleventh largest group of speakers in the world, approximately 73 million. Its dialects are mutually intelligible except for the Jeju (Cheyjwu) Island dialect, which retains old forms but is becoming endangered.

Korean has an SOV (subject-object-verb) head-final feature like Japanese and unlike Chinese or English. Sentence types such as declarative, interrogative, imperative and promissive are distinguished by means of markers that appear at the end. Nominals take case markers or postpositions after them and verb stems take tense, modal, speech level, and S-type markers linearly in that order after them agglutinatively. It is similar to Japanese in this respect. Honorification is a pragmatically motivated syntactic agreement phenomenon to show the speaker's respect for the subject. Speech levels mark the speaker's various attitudes toward the hearer including (non-)politeness. Honorification in Korean is a little more grammatical than in Japanese. The three East-Asian languages are topic-prominent, with object deletion via topicality unlike pro-drop languages such as Romance languages, although Korean and Japanese have subject or nominative markers as well as topic markers, unlike Chinese. Korean and Japanese have SOV in both matrix and embedded Ss unlike German. Korean and Japanese have a null argument in a relative clause, which is coreferential with the head noun on the right hand side of the clause.

Purpose

The purpose of this paper is to examine the acquisition of the topic marker –(n)un and the subject (nominative) marker –i/-ka in Korean. We will be concerned, in particular, with the way in which these case markers are produced over time, considering children's spontaneous speech as well as experimental data at several developmental time points. In this inquiry, we will be interested to find out how Korean children use or drop these markers on noun phrases, as well as how they produce or omit the entire topic/subject phrases over time, based on the pragmatic and syntactic properties governing them. We show the following developmental sequence of the stages: null topic/subject → bare nominal topic/subject → marked topic/subject. Once these markers emerge, the developmental sequences for the functions of the topic and subject markers are: contrastive topic → global/thematic topic and focus subject → neutral subject. The latter two sequences are surprising in terms of markedness because they proceed from ‘marked’ to ‘unmarked’, unlike the sequence null → bare → marked for the use and marking of topic and subject noun phrases.

Korean

Word order and case markers

As is well-known in the literature, Korean word order is, in general, regarded as fairly flexible; the preferred word order is either the SOV pattern, or a combination of SOV and OSV structures. Word order can vary for a variety of reasons, including topicality, focus, and emphasis, among others.

This is the third and last volume of the three-companion-volume series on East Asian psycholinguistics. East Asian here includes Chinese, Japanese and Korean, the languages that have received increasing interest in psycholinguistic research beyond the Indo-European languages. The three languages reveal extremely interesting typological characteristics; Japanese and Korean are strikingly similar in structure and various other respects, although they show surprisingly important and subtle differences. Chinese, on the other hand, contrasts more sharply with Japanese and Korean in typological patterns, although the three share certain areal commonalities such as the use of numeral classifiers. Korean and Japanese are similar grammatically, but not lexically and phonologically. Because of many commonalities in grammar, the two languages are often compared and contrasted linguistically and psycholinguistically (see Japanese/Korean Linguistics 1 to 15, CSLI, among others). Korean is generally hypothesized to belong to the Altaic language family, which encompasses Manchu-Tungusic, Mongolian, and Turkic languages. Japanese is also often believed to be an Altaic language, whereas Chinese belongs to the Sino-Tibetan language family. Korean and Japanese are thus distinct from Chinese genetically and typologically. However, the two languages have a vast amount of culturally borrowed Sino-Korean and Sino-Japanese lexical items, respectively, even adopting Chinese characters minimally in Korean and vastly in Japanese in their writing systems.

Therefore, the idea of the trio in companion volumes is crucial for comparative studies, not only among the three but also between the three and other languages including English.