Additive Language Learning for Multilingual Settings

Most people around the world speak more than one language and many more would like to do so.  Africa, for example, is home to about one-third of the world’s languages, and most people there use multiple languages to communicate in different domains and settings.  Yet the rich linguistic environment of most countries has been a challenge for policymakers and educators, who are faced with difficult questions: what should a language policy for education look like? How do children learn to read in different languages? What level of knowledge of a language is required before children benefit from education using a new language as a medium of instruction? 

This paper aims to answer this last question: when can the medium of instruction successfully include more than the mother tongue? It also explores ways to determine this threshold level of knowledge and whether this threshold level is different for different languages.