Abstract
This study examines the productive knowledge of synonyms in English by 40 Saudi EFL learners. It also tests whether the participants' English proficiency level plays a role in their production of English synonyms. To this end, the researcher designed a translation test to measure Saudi EFL learners' ability to produce the correct synonym in contextualised English sentences. In order to test whether the English proficiency level of the participants influenced their production of English synonyms, the participants were divided, on the basis of their scores on the Oxford Placement Test, into two groups: 20 Advanced Learners (ALs) and 20 Intermediate Learners (ILs). The answers of the two groups on the translation test, i.e., the ALs and ILs were compared to check whether their English proficiency level played a role on their answers. A Chi-square test was employed to determine whether the differences between the ALs and ILs on the test were statistically significant. The results show that the number of correct answers provided by ALs was higher than that provided by ILs, suggesting that their English proficiency level may have played a role in their answers. The study suggested that the main sources of error were L1 interference, lack of focus on the acquisition of vocabulary in schools in Saudi Arabia, lack of knowledge of some English lexical items, lack of awareness of the different nuances of meaning between the synonyms in English and lack of knowledge with English collocations. Finally, the study concludes with some recommendations for further research.