生物医药英语的动词体系实证探究

With the rapidly increasing international academic exchanges, English for Special Purposes (ESP) has received considerable attention in terms of teaching and research. A more serious challenge for Chinese EFL learners is to present and share their own understanding of knowledge in their respective fields in English. Since domain knowledge includes not only individual terms and concepts, but more importantly the relationship between concepts, to present such knowledge often involves verbs to define concepts and to describe and explain their relationships. Therefore, an empirical study of the verb system in biomedical English can help uncover some distinctive linguistic features specific to this discipline that enables the clear and precise presentation of biomedical knowledge and to shed light on the teaching and writing of biomedical research papers. The current study, based on a large corpus of biomedical abstracts, investigated the verb system of biomedical language in terms of transitivity types and lexical instantiations.
A self-built corpus of 164, 315 biomedical abstracts was built from the PubMed, with a total number of over 46 million running words. For a better understanding of the linguistic features of biomedical texts, two general corpora (i. e. the Brown Corpus and the LOB Corpus) were used as reference corpora. All the three corpora were then annotated automatically with a tagger named AUTASYS. The fine-grained POS tagging scheme used in AUTASYS embodies the transitivity of VPs, including eight sub-divisions such as intransitive, copular, and mono-transitive, and it also includes an additional feature indicating the grammatical status such as present-tense mono-transitive verbs.
The investigation of the verb system in biomedical texts can be summarized in the following three aspects. First, a general survey of the 20 most frequently used verbs in the three corpora revealed that biomedical language exhibited a preference for lexical verbs over delexcial verbs. Delexcial verbs, often with more than one meaning, are more likely to produce ambiguity and therefore are avoided in formal registers. Employing more meaning-specific lexical verbs suggests formality and accuracy in biomedical language. Second, a close look at the distributional features of verb transitivity showed a distinct preference for mono-transitive verbs in biomedical English, in contrast to a balanced preference for mono-transitive and intransitive verbs observed in general English. Since a mono-transitive verb requires one direct object, the preference for mono-transitive verbs indicates that a possible higher occurrence of single bio-events in biomedical texts. The findings suggested that the description of the subject-object relationships could be important to the construction of the knowledge in the biomedicine domain. Such a verb construction could also help maintain the precision of the message, a quality required in formal writing. Third, a further analysis of the verb form revealed a strong preference for the past participial (-edp) form in biomedical English versus a clear preference of past tense in general English. A follow-up examination of the auxiliary system showed that PubMed had a predominant use of the passive auxiliary, thus suggesting the higher proportion of -edp verbs is the result of passive constructions instead of perfective use. Therefore, the evidence suggested that passive voice was still widely used in biomedical English. It would be safe to say that the three linguistic features of biomedical texts in terms of verb transitivity also demonstrate the level of formality in scientific texts.