Register-sensitive Translation: a Case Study of Mandarin and Cantonese (Non-archival Extended Abstract)

Register-sensitive Translation: A Case Study of Mandarin and Cantonese Tak�sum�Wong� ������������������������� John�Lee�� �������������������� �������������������������������������������������������������������������� ���������������������������� � Abstract This paper describes an approach for translation between Chinese dialects that can produce target sentences at different registers. We focus on Mandarin as the source language, and Cantonese as the target. Mutually unintelligible, these two varieties of Chinese exhibit dif- ferences at both the lexical and syntactic levels, and the extent of the difference can vary considerably depending on the register of Cantonese. Since only a modest amount of paral- lel data is available, we adopt a knowledge-based approach and exploit lexical mappings and syntactic transformations from linguistics research. Our system parses a source sen- tence, uses register-annotated lexical mappings to translate words, and then performs word reordering through syntactic transformations. Evaluation shows that translation models that match the required register of the target sentences yield better translation quality. 1. Introduction A large number of Chinese dialects are spoken in different regions of China. Many of these dialects are not mutually intelligible (Killingley, 1993; Szeto, 2000); indeed, the differences between the major Chinese varieties have been described as being “at least on the order of the different languages of the Romance family” (Hannas, 1997: 198), or “roughly parallel to Eng- lish, Dutch, Swedish, and so on among the Germanic group of the Indo-European language family” (Mair, 1991: 3). This paper describes an approach for translating between Chinese dialects, focusing on Mandarin as the source language and Cantonese as the target language. Mandarin, also known as P�t�nghuà, is considered standard Chinese and is the domi- nant variety in mainland China. Spoken by more than 55 million people, Cantonese, the “most widely known and influential variety of Chinese other than Mandarin” (Matthews and Yip, 2011), is the dominant variety of Chinese spoken in Hong Kong. In Hong Kong, Can- tonese is used mainly in speech, while Mandarin is dominant in written contexts. This divi- sion of labor is somewhat comparable, for example, to the usage patterns of Swiss German dialects and standard German in Switzerland. Although mutually unintelligible in their spoken form, Cantonese and Mandarin are genetically related, having both developed from Middle Chinese. They share similar writing systems, as well as many cognates. Most Mandarin lexical items can also be used in Canton- ese. In a study on the Leipzig-Jakarta list of 100 basic words (Tadmor et al., 2010: 239–241), 60% of the Mandarin-Cantonese word pairs have identical written forms, most of which have highly regular phonological correspondence; a further 20% have the same core morpheme (Li et al., 2016). However, lexical items in Cantonese can vary considerably depending on the register, i.e., language variation according to context (Halliday and Hasan, 1989; Quirk et al., 1985). Low-register Cantonese, typified by casual, informal speech, is often peppered with lexical items that are not used in Mandarin; in higher-register Cantonese, more lexical items are shared with the standard Chinese lexicon. Put otherwise, “an increase in informality cor- Proceedings of AMTA 2018, vol. 1: MT Research Track …

Content truncated to 500 words