本論文探討台灣閩南語（TSM）的入聲中和與變調現象。研究採用田野調查數據及優選理論（Optimality Theory, OT）進行分析。根據台灣中部語者的數據顯示，該地區大多數台語母語人士在範域中的詞尾位置（domain-final positions）逐漸將第八調（T8，高入聲調）與第四調（T4，低入聲調）合流，僅保留低音域，不過有少數語者在相同位置仍維持高低調的區別。然而，在非詞尾位置時（domain non-final positions），T4和T8皆遵循台語變調規則，並在變調後保留高低音域的區別。上述現象顯示中和作用正在進行當中，並有持續擴張的趨勢。由於音調改變的現象擴張（overapplication）至非變調位置會產生隱晦性（opacity），導致傳統優選理論難以預測，因此，更詳細的制約及排序至關重要，以捕捉此一現象。
本研究採用兩種方式來預測該現象：比較有標制約（Comparative Markedness, CM）與反信實制約（Anti-faithfulness, AF）。CM藉由區分舊與新的有標特徵來驅動音域轉變，而 AF 則透過要求違反信實制約來強制交替。在 CM的例子當中，*OCHECKED-HIREG 排序最高，以阻擋高入聲調的衍生。AF則將¬ID-CHECKED-HIREG排在首位，迫使高入聲調必須與本調形式不同。兩種方法皆成功捕捉所觀察到的現象，但呈現了不同的理論意涵。CM透過應用舊與新的標記制約來捕捉底層到表層的衍生狀態，而AF則強制音調的直接轉變。

This thesis investigates checked tone neutralization and tone sandhi phenomenon in Taiwanese Southern Min (TSM). The analysis is conducted using fieldwork data and Optimality Theory (OT). Based on the data from speakers in central Taiwan, the study reveals that most TSM native speakers in this area has increasingly converged T8 high checked tone with T4 low checked tone in domain final positions, preserving only the low register form. Only a few speakers maintain distinction between high and low tones in the same positions. However, in domain non-final positions, both T4 and T8 follow TSM sandhi rule and retain the distinction between high and low after the tonal shift. The above-mentioned phenomenon indicates that neutralization is in progress. Due to the overapplication of tone shifting, the opacity is found; it is important to capture more detailed constraint rankings in this phonological variation.
To account for these patterns, the analysis employs two complementary theoretical approaches, Comparative Markedness (CM) and Anti-faithfulness (AF). While CM motivates the register shift by distinguishing old from new marked features, AF enforces alternation by requiring the violation of faithfulness constraints. In the case of CM, *OCHECKED-HIREG ranks the highest to block high checked tone from deriving. AF, on the other hand, ranks ¬ID-CHECKED-HIREG at the top, so that high checked tone is forced to differ from the citation form. Both approaches successfully capture the observed phenomenon but perform different theoretical implications. While CM capture the derivational status applying old and new markedness constraints, AF enforces obligatory alternation.

Alderete, John D. (2001). Dominance effects as transderivational anti-faithfulness. Phonology 18, 201-253.
Ang, Ui-jin. (1985). Taiwan Helaohua Shengdiao Yanjiu [Tone research on Taiwanese Hokkien]. Taipei: Independence Evening Post.
Ang, Ui-jin. (1992). Taiwan Fangyan zhi Lyu [The Journey of Taiwan Vernacular]. Avanguard Publishing House.
Ang, Ui-jin. (1997). Kaohsiungxian Minnanyu Fangyan [Southern Min Dialects in Kaohsiung County]. Kaohsiung County Government.
Ang, Ui-jin. (2019). Langauge Atlas of Taiwan. Avanguard Publishing House.
Chang, C.-H. (1989). Taiwan Minnan Fangyan Jilue [Notes on Southern Min Dialects]. Liberal Arts Press.
Chao, Yuen Ren. (1930). A system of tone letters. Le Maître Phonétique 45:24–27.
Chen, Su-Chuan (2009b). The vowel system change and the Yin-/Yang-entering tonal variations in Taiwanese Hokkien. Journal of Taiwanese Language and Literature, 3, 157–178.
Chen, Su-Chuan (2010b). New sound variation in Taiwan Southern Min: Vowel systems and the lower register entering tone in Taipei, Changhua, and Tainan. Language and Linguistics Compass, 11(2), 425–468.
Chen, Su-Chuan (2013). The sound variation and change of Shezi dialect in Taipei City. Language and Linguistics, 14(2), 371–408.
Fon, Janice & Khoo, Hui-lu. (2024). The Phonetics of Taiwanese. Cambridge University Press, Cambridge.
Hsiao, Yuchau E. (2015). Rethinking OCP Effects on Tone Sandhi. Language and Linguistics.
Hsiao, Yuchau E. (2015). Tonal chain shifts in Taiwanese: a comparative markedness approach In: Yuchau E. Hsiao and Lian-hee Wee, eds. Capturing Phonological Shades within and across Languages. Cambridge Scholars Publishing, Cambridge.
Hsiao, Yuchau E. (2020). The Competition between syntax and rhythm in iGeneration Taiwanese. Proceedings of the Linguistic Society of America, 5(1). 94–99
Jongman, A., Qin, Z., Zhang, J. & Sereno, J. A. (2017). Just noticeable differences for pitch direction, height, and slope for Mandarin and English listeners. Journal of the Acoustical Society of America, 142(2), EL163–EL169.
Liao, Jui-Chang. (2003). Investigation on the Entering Tones in Taiwanese, MA thesis, National Hsinchu University of Education.
Lin, Hui-shan. (2000). Tone Sandhi in Taiwanese, in Mandarin and in Taiwanese-Mandarin Code-mixing. MA thesis. National Chengchi University.
Lin, Jia-Chen. (2021). Identifiability and Discriminability of Tone Perception in Taiwanese Southern Min. MA thesis. National Taiwan Normal University.
Ling, Wang-chen. (2015). Circular Tonal Chain Shifts in Jiaoxian Compound Words. Language and Linguistics, 16(6), 873–889.
McCarthy, John J. (2003). Comparative markedness. Theoretical Linguistics 29: 1-51.
McCarthy, John J. (2008). Doing Optimality Theory. Malden, MA & Oxford, UK: Blackwell.
Pan, Ho-hsien. (2017). Glottalization of Taiwan Min checked tones. Journal of the International Phonetic Association, 47(1), 37–63.
Pan, Ho-hsien., Huang, Hsiao-tung, & Lyu, Shao-ren. (2016). Coda stop and Taiwan Min checked tone sound changes. Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH.
Prince, Alan, & Paul Smolensky. (2004). Optimality Theory: Constraint Interaction in Generative Grammar. Malden & Oxford: Blackwell.
Tung, Chung-Szu. (1996). Taiwan Minnanyu Yuyin Jiaocai Chugao [A Preliminary Manuscript on the Teaching Materials for Taiwan Southern Min Phonetics]. Council for Cultural Affairs, ROC.
Wee, Lian-Hee. (2020). A spin to preserve contrast: Taiwanese tone sandhi. Stellenbosch Papers in Linguistics Plus, 60, 13-29.
Yang, Hsiu-Fang. (1991). Taiwan Minnanyu Yufa Gao [A Manuscript on the Grammar of Taiwanese Southern Min]. Ta-an Press.
Yip, Moira. (2002). Tone. Cambridge University Press, Cambridge.