| The present study investigates Vietnamese EFL learners' acquisition of the pronunciation of the English interdental fricatives /theta/-/th/ and tense-lax vowels /i/-/I/ and /u/-/upsilon/. Two groups of Vietnamese EFL learners of pre-intermediate and advanced levels participated in the study. The target sounds were elicited through participants' readings of a word list and a text. The analyses involved descriptive stastistics, MANOVAs and spectrograms. The results showed that proficiency had a significant effect on Vietnamese EFL learners' pronunciation of the English interdental fricatives /theta/-/th/ in initial and middle positions, both in the word list and context, but there was no significant effect on the pronunciation of the tense-lax vowels /i/-/I/ and /u/-/upsilon/. Gender differences in the production of the interdental fricatives and tense-lax vowels were not significant. The findings of the study indicate that explicit training and practice may facilitate learners' acquisition of those sounds. |
