The Linguistic Effect of Foreign Language Learning on the Development of Mother Tongue Skills

This article describes how foreign language learning influences mother tongue development and use in a decisive period (ages 14–16) when the acquisition of the mother tongue skills is intensive, and individual writing, learning, and problem solving strategies and styles are being developed. It is argued that intensive and successful foreign language learning supports first language (L1) development significantly. Findings are based on a longitudinal experiment that was conducted in Hungary in 1988–1990 with native speakers of Hungarian learning either English, French, or Russian in different types of secondary schools. During the experiment only written language was examined; therefore, all the findings and conclusions refer only to the use of written language.