This study investigated the effectiveness of an intelligent computer-assisted language learning (ICALL) program on learning word classes to Turkish learners of English. Learning word classes is a common problem for Turkish students, so the main aim of this research is to help students to overcome this problem. Within the scope of this research, an ICALL application with a word class analyzer was developed and used on Foundation English School Students to measure its effects on students’ achievement in the mastery of word classes and also their attitudes toward such an ICALL environment. The study employed a pre-test—post-test control group design. The sample consisted of 38 B1 level students who were divided into experimental and control groups. The t test was used to investigate the differences between the experimental and control groups. Learners’ achievements in the knowledge of word classes were measured. The results showed that the reading activities with this system had positive effects on students’ word classes learning and their attitudes toward the intelligent computer-assisted language learning tool. According to the statistical results obtained from the study, there is a significant difference between the groups in favor of the experimental group.