| This thesis reports a study which was undertaken to investigate the use of causal connectives by English majors in their argumentative compositions, both spoken and written, elicited with the same topic prompt in a test setting. On the basis of the general description of occurrence of the causal connectives in the learners’speaking and writing, the present research seeks to examine the differences in the learners’use of causal connectives across their oral and written argumentative writings and across their different English proficiency levels. Effort was also made to examine the correlation of the frequency and variety of causal connectives to the learners’different English proficiency. The ultimate goal of this research is to explore to what extent the use of causal connectives may affect the learners’English proficiency in terms of discourse strategy.The materials employed in the study consist of two parts. The oral data was extracted from the SWECCL, a corpus of spoken English produced by English majors in a testing context, in which60cases were selected from the learners’ monologic utterances elicited by the speaking task of talking on the topic of "Pets or not". The selected cases were re-grouped and classified into20high-level cases and20low-level cases according to the test participants’oral performances. The written part was collected from60argumentative writings by the juniors in a timed condition. Similarly, the written data were divided into high-level and low-level groups according to the scores given by three test scorers. The data was then analyzed qualitatively to identify and categorize causal connectives in both learners’ oral and written argumentative compositions. Statistical calculation and data analysis generated the following major findings:Firstly, unexpectedly, there are limited occurrences of causal connectives identified in either oral or written compositions on an argumentative topic, accounting respectively for1.6%and1.2%of the investigated spoken and written data, and the occurrences of causal connectives can be categorized into three types:conjunctions, adverbial phrases and prepositional phrases.Secondly, of all the identified causal connectives, the most frequently used are the short and simple conjunctions which enjoy similar occurrences in both oral and written compositions. The conjunctions are followed by adverbial phrases in terms of frequency of occurrence, and the least used are the prepositional phrases. The independent samples t-test conducted reveals that there is significant difference between oral and written compositions in the use of three types of causal connectives in terms of frequency, and more adverbial phases and prepositional phrases were found in the learners’ written compositions than that of in their oral compositions.Thirdly, the learners’ over-and under-use of some causal connectives reveal a similar tendency in both oral and written compositions, such as the over use of so and because, and scanty or no use of consequently, hence, in that and for that reason. This might be related to the learners’ low awareness of lexical variety or the logical structuring of information. It is also likely due to the paratactic nature of the learners’LI, which does not emphasize the explicit use of cohesive devices.Fourthly, independent-samples t-test shows that there is significant difference in the frequency of use of causal connectives between high-and low-level students, with higher achievers using more causal connectives in both speaking and writing, and using more adverbial phrases and prepositional phrases in the writings. This suggests that high-level students were likely more aware of cohesiveness and register differences.Finally, the correlation analysis reveals that frequency and variety and the students’ proficiency level are positively correlated but not at a significant level, which suggests that the frequency and variety of use of causal connectives should not be employed as a necessary indicator to the assessment of learners’performances in their oral and written production.The results generated from the data analysis may have some pedagogical implications:The influence of L1transfer may be one of the major factors for the learners’ less awareness and even ignorance of use of causal connectives and further, of differences of hypotactic and paratactic characteristics in Chinese and English languages. The forming reasons for learners’ improper use or underuse of causal connectives are likely related to different modes of thought. Therefore, the EFL instructors may start with the use of connectives in the development of English majors’ discourse ability to organize information in either speaking or writing. |