A corpus based study of the synonyms flammable, inflammable, combustible, and incendiary

The objective of this study was to investigate the near synonymy of the four English adjectives flammable, inflammable, combustible, and incendiary, emphasizing the collocations, formality/genre, grammatical patterns, connotations, and dialects of each adjective. The sources of data in this study included the (online) Longman Dictionary of Contemporary English (Online access), the (online) Oxford Advanced Learner’s Dictionary, the Corpus of Contemporary American English (COCA), and the British National Corpus (BNC). The results suggest that they are near-synonyms (Lyon, 1995). In addition, the findings revealed that the four adjectives share a similar core meaning which is ‘able to burn easily’, but have many differences in terms of collocations, formality/genre, grammatical patterns, connotations, and dialects. Although the adjectives differ widely in their collocations, there are also a number of nouns that can be collocated with two or more of the synonyms, such as the nouns ‘material’, ‘liquid’, and ‘gas’, which collocate with all four of the adjectives. In terms of formality and genre, the synonyms are quite similar in this aspect. In terms of dialectical differences, in COCA, the corpus that was used in this research to represent American English, incendiary and flammable are used more compared to other words (1,278 and 1,030 hits respectively), while combustible is less frequent (659 hits), and inflammable is barely used at all (66 hits). Interestingly, BNC, the corpus that represents British English in this research, shows that all four adjectives are close to each other in terms of frequency (75 for flammable, 53 for inflammable, 45 for combustible, and 85 for incendiary). With respect to the grammatical patterns of these adjectives, although many patterns are shared, only a handful are unique to an adjective; however, using intuition, the researcher’s opinion is that most of the patterns seen in the corpus can be safely used interchangeably. Lastly, concerning connotations, the findings show that almost all of the adjectives appear in sentences with negative or neutral tones, and some of the adjectives can be used to describe a characteristic of speech or piece of writing that is ‘provocative’ in nature.