The focus of this paper is the use of one’s native or first language (L1) when learning English as a second language (L2). For many years, the preferred approach to learning English in a classroom has been to avoid the use of L1 (Cook, 2001). The study took place in an open Norwegian primary school and was conducted on 4th graders who had been taught English since 1st grade. Using the exploratory grounded theory approach the author made a learning experiment in which a text – a fairy tale – was introduced in L1 before the English version was read aloud to the students. This was followed by several tasks that made it possible to observe whether the L1 version had an influence on the learning objectives. The results indicated that L1 had a positive influence on vocabulary, grammar, and dialogue in the classroom. The use of L1 prompted students to have discussions about vocabulary and grammar connected to the fairy tale. The study also provided an unexpected insight into how non-Norwegian students found learning opportunities in working with the two languages.