English vocabulary acquisition is a major challenge for English as a second or foreign language learners to become proficient in English. It is also a major challenge for English speakers who are at risk. With the increasing use of various mobile devices (e.g., iPad) for educational purposes, we have a new opportunity to support vocabulary learning. Mobile devices have considerable potential for enhancing vocabulary acquisition and English learning among English learners. This article focuses on how mobile devices can be used to facilitate vocabulary learning for English learners. While there is a paucity of research on mobile platforms that enhance learning, we believe that a theoretical approach coupled with studies in vocabulary acquisition can point to relevant practices for all teachers and students. Based on these theories, we discuss how various mobile apps can be used to enhance vocabulary acquisition with four research-based vocabulary learning strategies: dictionary use, phonological analysis (i.e., learning words by analyzing the sound parts), morphological analysis (i.e., learning word meanings by analyzing the componential word parts), and contextual analysis (i.e., learning word meanings by referring to learning context)
