This paper discusses the teaching and learning of Arabic vocabulary with respect to the needs and desires of the modern learner of Arabic. It begins with an explanation of Arabic diglossia and a review of current research regarding the desires and goals of the modern Arabic learner. It then discusses the issue of teaching Arabic vocabulary showing that learning two varieties of Arabic at the same time, because it is a case of synonymy, creates a learning burden for Arabic learners but is nonetheless necessary. This paper then discusses a number of other reasons that make Arabic vocabulary acquisition a challenge and suggests possible methods to overcome this challenge. / text