This study investigated the use of English articles in five semantic contexts by pre-intermediate and intermediate level Turkish EFL students at a state university. Specifically, it explored a) whether the accuracy of article use by the students varied with respect to the types of noun phrase (NP) contexts b) the types of errors committed by the students in using English articles, and c) whether the accuracy of article use varied with respect to the proficiency levels and the tasks that the participants carried out. The data were collected through two task types: a multiple-choice (MC) task and a written production task. The results of these tasks revealed that the accuracy of article use by students varies with respect to the types of NP contexts in both the multiple-choice task and the written production task. Moreover, each proficiency level tended to omit or substitute the articles when they make a mistake. However, the variety and frequency of these errors depended on the proficiency level of the students, type of the NP contexts, and the tasks that were given to the students. The study also revealed that the accuracy of article use varied with respect to the proficiency levels, and the tasks that were given to the students.