In a study of the reliability of an English language proficiency test for non-native teaching assistants (NNS TAs), 18 NNS TAs were administered the SPEAK Test. The results were compared with student evaluations of the intelligibility and clarity of the TAs' classroom speech. Despite problems with the SPEAK Test, the measure was considered a valuable primary screening device. Several of the highest-scoring TAs on the SPEAK Test were not rated highly by students, suggesting the possibility of other variables affecting student evaluations. A questionnaire was administered to the students for evaluation of the TAs' communication style, and the students also completed the usual faculty evaluation form. The subconstruct "attentiveness" on the communicator style measure was the only variable showing a high degree of correlation with assessments of teacher performance. Videotapes of the TAs in a mock teaching situation were used to further examine the attentiveness factor in the classroom performance of three of the NNS TAs. It is suggested that teacher attentiveness can compensate for deficiency in English speech skills. The undergraduate student questionnaire is appended. (MSE)