Abstract
This paper investigates Arabic and English inflectional morphology with a view to identifying the similarities and differences between them. The differences between the two languages might be the main reason for making errors by Arab EFL learners. Predicting the sources of such errors might help both teachers and learners to overcome these problems. By identifying the morphological differences between the two languages, teachers will determine how and what to teach, on the one hand, and students will know how and what to focus on when learning the target language, on the other.