Das Werk besteht aus Hauptteil (Print + Online) & Appendices (nur Online) This doctoral dissertation investigates the linguistic performance of German elementary school English teachers and how their second language (L2) English performance relates to their students' acquisition of English as a foreign language. The studies reflect the teachers' L2 language performance, give insights into the interrelationships of the complexity, accuracy, and fluency (CAF) dimensions of L2 language production, and finally address how linguistic performance relates to the students' L2 development. Following a mixed-methods approach, the first study analyzed the language performance elicited in semi-structured qualitative interviews with eleven German elementary school English teachers based on CAF measures. The second study focuses on the students' language development of a sub-set of four of the interviewed teachers. The students (N = 132) were given picture pointing tasks of either receptive grammar, receptive vocabulary or both at two times during the fourth year of elementary school. The key finding was that the whole group’s mean grammar score significantly improved from time one to time two. The increase of the mean vocabulary score was not statistically significant. When the students were grouped with their respective teachers, comparisons exposed significant differences between some of the groups. The third study synthesizes the teachers’ CAF performance and the students’ development in receptive English grammar and vocabulary. A principal components analysis (PCA) first calculated the variability of the range of the measures for complexity, accuracy, and fluency and their contributions to each CAF dimension. Correlation analyses between the dimensions revealed several robust significant correlations for complexity, accuracy, and fluency as captured in breakdown fluency and speed fluency. Repair fluency and lexical diversity correlated with breakdown and speed fluency, but not with accuracy and complexity. Based on the teachers’ composite CAF scores calculated in the PCA and the students’ test scores, the relationships between the teachers’ language performances and their students’ L2 development were analyzed. Multiple regression analyses retained breakdown fluency, measured in the number and length of pauses as part of the fluency dimension, as the only dimension significantly predicting the students’ receptive grammar development. The results point to several conclusions: First, the significant correlations between complexity, accuracy, and fluency in terms of breakdown and speed fluency indicate that the dimensions did not come at the expense of one another in the L2 performance on the cross-sectional interview task used in this study. Second, the students’ significant improvement in receptive English grammar implies some positive development of elementary school L2 English as a whole. However, the high variability among the students’ scores indicates other factors being at play in the children’s L2 development in addition to the teachers’ performance investigated in this study. Third, breakdown fluency as a specific feature of the teachers’ spoken language performance may have a beneficial effect on the children’s receptive English grammar acquisition. This finding is in line with observations of pausing as an element of L2 teacher talk as well as a prosodic feature in child-directed speech in first language acquisition that potentially aids language learners in segmenting linguistic input. The findings propose that future research take into consideration specific features in the L2 input and examine them as possible factors in children’s L2 language acquisition.weiterlesen