Introduction

In Chapters 2 and 3, we introduced two key concepts regarding the distribution of sounds in a language: contrast and complementarity. Two or more sounds are contrastive if they appear in identical environments. They are complementary in their distribution if they appear in non-identical, mutually exclusive contexts. Contrast and complementarity play a key role in determining the status of sounds as either phonemes or allophones. We refer to the sounds whose distributions are contrastive as phonemes. We consider as allophones those sounds that are in complementary distribution and phonetically similar. Clearly, not all sounds are either contrastive or complementary in distribution. We demonstrated through the velar nasal ŋ in English that it appears to be partially contrastive, contrasting with other sounds in the syllable coda, but not in the onset. The exact status of ŋ as either a phoneme or an allophone of some other phoneme requires phonological analyses, a topic we will take up in Chapter 5.

This chapter reinforces your understanding of contrast and complementarity. The data come from standard Thai, the language spoken by the educated, middle-class population in the central region of Thailand, particularly in Bangkok. There are four sets of plosives in standard Thai: (a) voiced plosives [b, d]; (b) voiceless aspirated plosives [ph, th, kh]; (c) voiceless unaspirated plosives [p, t, k]; and (d) voiceless unaspirated and unreleased stops [p¬, t¬, k¬]. Some of these plosives are contrastive, while others are complementary. Part of the challenge of the Thai data is to determine which plosives are contrastive and constitute phonemes and which ones are complementary and are allophones of other phonemes. Moreover, there are potentially more than one set of phonemes from which allophones might be derived. Thus, the Thai data require considering the sources from which the allophones are derived.