The document discusses several popular assumptions about language learning from two sources. Lightbrown and Spada (2010) assert that motivation is the best predictor of success in language acquisition, though this depends on other factors like a learner's ability to access input. They also note that students learn what they are taught but their capacity and motivation can vary. Cook (2001) discusses beliefs from the 19th century around avoiding explicit grammar instruction and learning being best through spoken language due to theories about speech preceding writing. The document concludes that both teachers and learners must work together in the language acquisition process as it depends on many individual and contextual factors making it a collaborative 50/50 effort.