This study investigates contact-induced grammatical change with specific emphasis on the prefinal imperfectives –ang and -ag in Swahili. Strategies for marking tense and aspect in Swahili and Bantu languages have been analyzed in a number of books, book chapters and articles. Despite the incontrovertible upsurge in the use of prefinal imperfectives, particularly in communicative interactions amongst the youth in urban settings, investigations into this phenomenon are scarce. Based on naturally occurring data obtained in Nairobi, Kenya and observations and interpretations, this study attempts to analyze the morphosyntactic and semantic features of prefinal imperfectives –ang and -ag in Swahili. First, background information conducive to understanding this grammatical change is provided. This includes the standardization of Swahili and its impact on present-day Swahili, strategies to mark tense and aspect in Swahili and other Bantu languages, semantic features of imperfectivity in Swahili, the prominent roles of mimesis in acquiring a second language in contact situations, the S-curve of language change and its applicability, and the disadvantages of prescriptive grammar rules. All these key concepts and topics are interrelated, and less researched topics must be included to systemically and clearly explain language change. Accordingly, this study is designed to enhance our understanding regarding one of the aspects of grammatical change from both synchronic and diachronic perspectives.

Abstract
1. 서론
2. 선행연구
3. 스와힐리어의 표준화와 규범문법의 확립
4. 반투어와 스와힐리어의 불완료상
    4.1. 반투어의 시제 표지 전략
    4.2. 시제 이론과 상
5. 언어접촉과 문법적 변화
    5.1. 케냐 도시지역의 언어 역동성
6. 모방이 언어습득과 사용에 미치는 영향과 S-곡선
    6.1. 모방
    6.2. S-곡선
7. 형태와 의미적 특성
    7.1. 형태적 특성
    7.2. 의미적 특성
8. 맺음말
참고문헌
약어

• 양철준(Lecturer, Department of Linguistics, Seoul National University; 2-108, 1, Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea) | Chul-Joon YANG