''This paper scrutinizes the factors affecting L1 and L2 speech fluency, focusing particularly on self-repaired speech errors in English as L2 in the speech of native Serbian speakers. The research was conducted to examine the level of L1 lexis and grammar interference in L2 speech production due to the higher cognitive load during L2 speech production. Based on the content analysis of spontaneous speech in English as L2, this research aims to classify and interpret the detected self-repairs in terms of language segments affected by the reparanda, the prevalence and selection of editing terms, and the types and focus of repairs. The reparanda are further examined regarding the stage of the speech production process they occur in, as discussed in Levelt's production model as well as several bilingual speech models. Perceptual loops activated as the result of the monitoring mechanism during speech indicated that erring produced both general self-repairs and common L2-related self-repairs. Furthermore, one fifth of all self-repairs were classified as Serbian-related self-repairs, undoubtedly indicating the presence of L1 interference, even in highly fluent English speakers.
Keywords: speech errors, speech production models, monitoring, perceptual feedback, self-repairs, executive control, L1 interference.''