Arabic instructors’ and curriculum planners are faced with the question of what methods to adopt to raise learners’ awareness of the sociolinguistic reality of Arabic use within increasingly multidialectal and multilingual Arabic-speaking speech communities. The Integrative Approach has been proposed as one such method. The question remains, however, as to the successful outcome of such integration given the demands of learning multiple varieties, typically Modern Standard Arabic (MSA) and a variety (or more) of Colloquial Arabic (CA). To address this question, this study investigated productions by 70 students in the first three years of Arabic instruction at a major Arabic program in the United States. It aimed at measuring learners’ ability to develop competence in MSA and CA. It, therefore, explored (1) the features of speech that learners display, (2) the existence of systematic patterns in the participants’ speech productions, and (3) the participants’ awareness of appropriate register in their MSA-CA use. The productions included student presentations, class skits and discussions, and end-of-course interviews. A qualitative, multistep, data-driven analysis was performed, and marked features were identified. The findings showed marked similarities that reflect learners’ evolving competence in MSA and CA. The learners code-switched between the varieties in their use of words, phrases, and sentences in instances of intrasentential and intersentential mixing. As they advanced in their Arabic study, their choices seemed to reflect their awareness of the appropriate language forms depending on the context of use. The productions also showed patterns of diglossic code-switching found in the speech of Arabic speakers. The study supports the importance of making curricular decisions that embrace the multidialectal use of Arabic in the Arabic L2 classroom. It also calls for an attitudinal shift, viewing learners’ code switching as a successful utilization of linguistic resources and a representation of the multidialectal and multilingual realities of Arabic use.