Bilingualism has been found to have a positive effect on the acquisition of a third language. This article explores the different theories of third language acquisition, including the Cumulative Enhancement Model and the Linguistic Coding Differences Hypothesis, and how bilingualism can facilitate the learning of a third language. In addition, the article discusses the various elements of bilingual teaching, such as immersion and transitional bilingual programs, and how they can be used to promote bilingualism and biliteracy. The article concludes by highlighting the importance of bilingualism and bilingual teaching in promoting language learning and cultural understanding in our increasingly globalized world.