This dissertation presents experimental research on speech errors in Tunisian Arabic (TA). 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. TA's nonconcatenative morphology shows interesting interactions of phrasal and lexical constraints with morphological structure during language production and affords different and revealing error potentials linking 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 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 focused on root versus non-root exchanges and lexical versus non-lexical outcomes for root and non-root errors. Experiments 2 and 3 addressed between-phrase exchange errors focused 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 show that root and vocalic pattern exchanges were very rare and that 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 in grammatical category (experiments 2 and 3) pursued two principal questions, one concerning the error rate and the second concerning the error elements. The expectation was that 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 corroborated with the expectation. 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.