Abstract
This article aims to present the impact that the Task-Based Language Teaching (TBLT) approach had on students’ use of English for Specific Purposes (ESP) vocabulary and grammar structures. The study took place in a course designed for a group of 11 Mechanical Engineering students at the University of Costa Rica, who expressed their needs, lacks, and wants in a needs analysis stage. To gather the necessary data for designing, implementing, and evaluating this mixed-methods study, the researchers collected both qualitative and quantitative data, through formal and informal interviews with students and stakeholders, questionnaires, a language diagnostic test, feedback sessions with course observers and evaluators, and the researchers’ notes on students’ performance. The results show that the impact of the TBLT approach not only had a remarkably positive effect on the students’ use of ESP vocabulary and grammar structures but also helped them feel less nervous when being assessed and more prepared to do tasks in real life after participating in in-class simulations.