This dissertation presents experimental research on speech errors in Tunisian Arabic. The nonconcatenative morphology of Arabic shows interesting interactions of phrasal and lexical constraints with morphological structure during language production. The central empirical questions revolve around properties of "exchange errors". These errors can mis-order lexical, morphological, or sound elements in a variety of patterns. Arabic's nonconcatenative morphology affords quite different and revealing error potentials to link the production system with linguistic knowledge. The dissertation studies expand and test generalizations based on Abd-El-Jawad and Abu-Salim's (1987) study of spontaneous speech errors in Jordanian Arabic by experimentally examining apparent regularities in that data from real-time language processing perspective. The studies address alternative accounts of error phenomena that have figured prominently in accounts of production processing. Three experiments were designed and conducted based on an error elicitation paradigm used by Ferreira and Humphreys (2001). Experiment 1 tested within-phrase exchange errors with a focus on root versus non-root exchanges and lexical versus non-lexical outcomes for root and nonroot errors. Experiments 2 and 3 addressed between-phrase exchange errors with a focus on violations of the grammatical category constraint (GCC). The study of exchange potentials for the within-phrase items (experiment 1) contrasted lexical and non-lexical outcomes. The expectation was that these would include a significant number of root exchanges and that the lexical status of the resulting forms would not preclude error. Results reported in this dissertation show that root and vocalic pattern exchanges were very rare and that the word forms rather than root forms were the dominant influence in the experimental performance. On the other hand, the study of exchange errors across phrasal boundaries of items that do or do not correspond ingrammatical category (experiments 2 and 3) pursued two principal questions, one concerning the error rate and the second concerning the error elements. Does the incidence of error differ for these two conditions? The expectation was that the conditions would differ and the errors predominantly come from grammatical category matches. That outcome would reinforce the interpretation that processing operations reflect the assignment of syntactically labeled elements to their location in phrasal structures. Results reported in this dissertation show that between-phrase exchange errors predominantly come from grammatical category matches. However, exchange errors involving words of different grammatical categories were also frequent. This has implications for speech monitoring models and the automaticity of the GCC. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]