... VIETNAM NATIONAL UNIVERSITY HANOI UNIVERSITY OF LANGUAGE AND INTERNATIONAL STUDIES Đỗ THị KHáNH VÂN A research into the role and the use of first language in General-English classes at Hanoi University ... of the participants in the study With observation, participants may not realise that they are being watched so they not moderate their behaviour in any way thus the data gathered in unadulterated ... reason the researcher focused on vocabulary acquisition is that the acquisition of vocabulary has a central role in learning a second language (Sửkmen, 1997), and is of great significance to language...