Pfenninger, Simone E.2014-11-282014-11-282014-10Studies in Second Language Learning and Teaching, 2014, vol. 4, no. 3, pp.529-5562083-5205http://hdl.handle.net/10593/12237This study was designed to investigate the effects of age of onset and type of instruction on ultimate EFL attainment at the end of the period of normal schooling in Switzerland, measured in terms of written fluency, complexity, morphosyntactic accuracy, vocabulary size, and listening skills. Data were gathered from four groups of 18-year-old Swiss German learners of English: 50 were early starters who had attended an immersion (CLIL) program in elementary school and who continued CLIL in secondary school (EARLY CLIL), 50 had followed the same elementary school program but then received traditional EFL instruction after elementary school (EARLY MIX), 50 were late starters who began learning English immersively in secondary school, (LATE CLIL), while the other 50 attended a traditional EFL program in secondary school (LATE NON-CLIL). Results show that age of onset alone does not seem to be the distinguishing variable since early introduction of English in elementary school did not result in a higher level of proficiency when exposure to the language was limited to a few hours of class per week. The performance of the EARLY MIX participants was equaled and in certain areas significantly surpassed by the other groups, despite the additional five years of English study they had had in elementary school. The best results were found when early CLIL instruction was followed up by the use of English as an additional language of instruction in secondary school (EARLY CLIL group), which confirms the link between young starting age, implicit learning and long and massive exposureensecond language learningage effects in L2input effects on L2immersionCLILArtykułhttps://doi.org/10.14746/ssllt.2014.4.3.8