Classroom assessment is an essential component of teaching and learning. Still, the literature on language testing often highlights teachers' perceptions of designing classroom assessments with little concern about students' perceived realities. This study thus explores Taiwan university students' perceptions of summative and formative classroom assessment tasks in their English courses. To address this issue, 107 first-year undergraduates at one Taiwan university were recruited to complete one summative written exam and two formative assessments, after which they filled in a questionnaire consisting of six subscales: congruence with planned learning, authenticity, student consultation, transparency, diversity, and washback effects. We discover four major findings: 1) students were in favor of the summative assessment due to its congruence with planned learning and transparency; most students admitted that they learn more from preparing for the summative assessment; 2) students viewed the cooperative group assessment positively, because of its diversity; 3) preparation for summative assessments elicited a greater degree of test-oriented learning for respective skills, whereas formative assessments enhanced students' motivation to learn English for productive skills; and 4) students believed that an appropriate combination of summative and formative assessment tasks benefits their learning. The findings provide further pedagogical implications.