1 Introduction

Explored the importance of English for Academic Purposes (EAP) and emphasized the crucial role of adverbs in conveying the author's views, attitudes, and evaluations. At the same time, it is pointed out that the characteristics of adverbs in the EAP field have not been fully studied, which is particularly difficult for non-native English speakers to master.

2 Research Review

Cognitive adverbs play an important role in academic writing, as they not only indicate propositional information and sources, but also convey the author's evaluation of the certainty, reliability, and limitations of propositional information, as well as their attitude towards the source of information. These adverbs have implicit persuasive functions and help achieve interpersonal meaning. Although there is controversy in the field of grammar regarding the classification of adverbs, most studies believe that cognitive adverbs are subclasses or parallel relationships of evidential adverbs. Empirical research shows that there are differences in the frequency and function of cognitive adverbs in different disciplines, and scholars at home and abroad also have differences in the use of adverbs. Domestic scholars have found that Chinese authors tend to use deterministic position adverbs, while foreign research has pointed out that Chinese learners have differences in the use of certain adverbs compared to international journal articles. This study aims to fill the gap in existing research by comparing the usage characteristics of cognitive adverbs in the English abstracts of doctoral dissertations in China and the United States, and systematically exploring cognitive adverbs from an interdisciplinary and cross linguistic perspective.

3 Research Design

This chapter elaborates on the research design of the use of cognitive adverbs in the English abstracts of doctoral dissertations in China and the United States. The study selected 400 English abstracts of Chinese and American doctoral dissertations in the fields of linguistics and petroleum engineering from 2016 to 2020 as the corpus, with 184279 in the Chinese doctoral dissertation abstract corpus and 74932 in the American doctoral dissertation abstract corpus. The research is based on the cognitive adverb concepts and categories proposed by scholars such as Quirk et al, Halliday, Biber et al, Simon Vandenbergen u0026 Aijmer, and others Hyland、Huddleston u0026 Pullum、McEnery u0026 Kifle、Wierzbicka After summarizing the vocabulary of scholars, 101 cognitive adverbs were extracted and classified into four categories based on semantic categories: conviction, attitude, frequency, and evidential. The research aims to compare and analyze the similarities and differences in the use of cognitive adverbs and their four subclasses between Chinese and American doctoral students from a cross linguistic and interdisciplinary perspective.

4 Results and Discussion

In the English abstracts of doctoral dissertations in China and the United States, the use of cognitive adverbs shows similarities and differences in language and disciplinary dimensions. Chinese and American doctoral students have reached a basic agreement on the pragmatic functions of cognitive adverbs, but the distribution of the four subcategories is uneven. The frequency and proportion of the use of adverbs are the highest, while the use of evidential adverbs is the lowest. The impact of disciplinary differences on CLD and CPD is greater than that on ALD and APD, and the level of mastery and research type of adverbs by non-native English speakers has a greater impact on cognitive adverbs than language background and disciplinary attributes.

5 Conclusion and Inspiration

Research has found that familiarity with native language and research methods affects the use of cognitive adverbs. There is no significant difference in the use of cognitive adverbs between Chinese and American doctoral students, but Chinese doctoral students are convinced that they use too many adverbs and not enough attitude adverbs. Chinese stonemasons are closer to native speakers in the use of affirmative and attitudinal adverbs. Disciplinary differences exist among Chinese doctoral students, while they do not exist among American doctoral students. The impact of research methods on the use of cognitive adverbs is greater than that of disciplinary fields. Chinese doctoral students need to improve their semantic and pragmatic control of adverbs, and reduce the phenomenon of inaccurate expression. The research results have implications for ESP teaching, and students should be guided to familiarize themselves with the language features of subject discourse communities and specific discourse, master the semantic connotations, pragmatic functions, and domain characteristics of cognitive adverbs, in order to more accurately and appropriately express research content.