Most Taiwanese universities and colleges offer a wide selection of English courses, compulsory or elective to cater to student needs. Compulsory courses are usually prerequisites for selective courses, except when students can prove an exceptionally high proficiency level with authenticated evidence, then the course can be waived and take selective courses immediately upon entering the college. Based on course objectives, elective courses are at a higher standard, or difficult, in terms of course goals, content, and tasks. Therefore, these courses can be compulsory basic English and selective advanced English. However, do students in these two kinds of courses really differ in terms of proficiency? If yes, to what extent do they differ? If this is truly the case, how should teachers deal with the situation of same level students but two different leveled courses? The results indicated that the participants in this study do not have significant differences in terms of vocabulary size and standardized tests. Therefore, the author offers some pedagogical advice based on the literature and their own experience and suggestions for future studies.