Task-Based Language Teaching (TBLT) is considered innovative in foreign language teaching. However, the body of research on TBLT employment in vocabulary instruction is still modest. This study explored teachers’ beliefs and practices regarding vocabulary instruction using TBLT. This study examined such application among Vietnamese high-school EFL teachers (N = 60) using a mixed methods research design. Data were collected using online questionnaires. Data analysis showed that 53.6% of the participating teachers associated vocabulary instruction with TBLT. However, regardless of their years as instructors, they still found it challenging to implement TBLT vocabulary instruction due to numerous factors. In fact, 66.2% of the participating teachers acknowledged a variety of constraints in applying TBLT, among which, exam-oriented curricula were reported as the biggest impediment.

Studies about native and non-native language teachers have found that these two groups are perceived as different from each other in language abilities and teaching styles. However, most of the existing research has investigated the perspective of teachers or students separately and has rarely triangulated their opinions. Therefore, the purpose of this study was to contribute to the body of literature related to the native and non-native teacher dichotomy by triangulating perceptions from native and non-native teacher samples and a student sample. Particularly, this study set out to examine the problem in the context of the English language teaching and learning system in Vietnam. This study involved three participant groups: 30 native English teachers (NETs), 30 Vietnamese teachers (VETs), and 30 Vietnamese EFL students in Vietnam. The instrument included two versions of an online Likert scale survey, one for the students and the other for the teachers (both NETs and VETs). The questions covered 4 areas of teaching efficacy: teaching language skills, teaching language aspects, teaching methodology, and assessment. The data were analyzed through statistical analyses, including Cronbach alpha, two MANOVAs, and 16 dependent t-tests. The results of this study revealed that NETs, VETs, and students did not differ significantly in how they perceived the teaching efficacy of NETs and VETs. Instead, they had similar judgments which overall were in the upper part of the scale, showing rather positive perceptions of the teaching efficacy of both NETs and VETs. NETs were favored in teaching pronunciation; teaching culture; teaching speaking; involving students; balancing lecture, pair work, and group work; organizing classes; measuring students' progress; and grading. VETs were found more effective in teaching grammar and giving feedback. Both NETs and VETs were perceived as equally effective in teaching listening, teaching reading, teaching writing, teaching vocabulary, preparing classes, and giving an appropriate number of tests.