This study examines supplementary English instruction as a supportive method in optimizing English input in Swedish multilingual classes in grades 1-3. Sweden has a high English proficiency and Swedish children enter school with increasingly advanced levels of English. Despite these positive facts, students in grades 1-3 only have 60 hours in total designated to the subject English. Studies suggest that Swedish students acquire more English from extramural exposure than in school. Schools that do not promote students’ further learning are in fact violating the fundamental tasks written in the Swedish national curriculum. In order to increase and optimize English learning opportunities for the younger students, schools are allowed to offer a maximum of 50% of the total teaching in English. The aim of this study is to explore if this approach of supplementary English instruction could benefit multilinguals. This is crucial, considering the great number of students with immigrant backgrounds who are learning English as a third language. This opportunity has resulted in various implementations of CLIL (Content and Language Integrated Learning). Several studies support an early introduction of CLIL, in order to promote bilingualism. The majority of CLIL-students achieve favorable results, thanks to the combination of intense linguistic input when in multilingual classrooms. Based on the findings of this study, supplementary English instruction offers the greatest advantages and is most popular precisely among multilingual students.