In this paper, we conduct experiments using F0 contour features to assess the nativeness of responses provided by speakers from India and China to a Sentence Repeat task in an assessment of English speaking proficiency for non-native speakers. The results show that the coefficients from polynomial models of the pitch contours help distinguish between native and non-native speakers, especially among females. We find that the F0 contour can be represented adequately by using only basic statistical variables and the first three orders of polynomial coefficients. In addition, the most important features for classification are presented for each group of speakers. Finally, we discuss the differences among the gender-specific groups of the speakers.