ABSTRACT Erlangga, Muhamad Eginda (2024) An Investigation of Vagueness Manifestations in Students’ Arguments within English Debate and Critical Thinking Course. An Undergraduate Thesis. English Education Department. Faculty of Education and Teacher Training, Universitas Tidar. Advisor I Gilang Fadhilia Arvianti, S.S., M. Hum., Advisor II Taufik Arochman, M.Pd.. Keywords: vague langua…