Vowel adaptation in English loanwords in Thai

Abstract

The use of English loanwords in everyday conversations of native Thai speakers is prevalent since many English words have been introduced to the Thai lexicon over the past 200 years. The nativisation of English loanwords into Thai has been carefully investigated in the last three decades; however, previous studies of Thai loanword phonology have primarily focused on consonants and tone assignment. Phonological adjustments made to the vowels have been less well-studied. This thesis investigates the phonological adaptation of English loanwords in Thai, focusing on adaptation patterns of monophthongs and diphthongs, and strategies employed to resolve non-native syllable structures which are ill-formed in Thai. The study examines the phonological processes that are involved in the Thai adaptation of English vowels, investigates how the best match for non-native vowels is determined and explores the role of native phonology in vowel adaptation. The loan data examined in the study were mainly drawn from standard Thai dictionaries. The analysis is conducted within the framework of Optimality Theory (OT) to explore how the grammar of the borrowing language deals with non-native segments and syllable structures which are ill-formed in the native language. The OT analysis demonstrates that English vowels which are not in accord with markedness constraints cannot surface in Thai, and their best matches are determined on the basis of acoustic closeness together with the phonological structure of the borrowing language. It also reveals that different repair strategies for imperfect syllable structures in native words and loanwords result from distinct constraint rankings for native lexical items and foreign words. The adaptation patterns identified in the loan corpus appear to show, firstly, that the phonetic characteristics of source vowels which are contrastive in the borrowing language are faithfully preserved in their adapted form, giving rise to phonological perception; secondly that a range of factors including phonetic, phonological, and non-linguistic factors are involved in determining how English vowels are realised in Thai; and thirdly that orthography plays a role if adaptation is underdetermined by other factors.