... 10th, 11th and 12th grade, using the standard English textbooks, i.e. Tieng Anh 10, Tieng Anh 11 and Tieng Anh 12. Because this study investigated the use of oral corrective feedback by ... 235 beloved students in seven classes including 10D1, 10D2, 10D5, 10Q1, 11D3, 12A2 and 12A3 at Phan Đình Phùng high school, who spent time completing my questionnaire in detail. I would like to ... interviews. Appreciation is also expressed to five main English teachers in seven classes at Phan Đình Phùng high school who allowed me to conduct classroom observations and some other teachers...