English as a New Language Early to Middle Childhood National Board Component 1 Practice Exam

The threshold hypothesis says that reaching a minimum level of L1 proficiency supports successful L2 learning. When a learner has a solid foundation in the first language, they can transfer underlying linguistic knowledge—grammar concepts, vocabulary organization, phonological awareness—and metalinguistic skills to the second language. This transfer makes it easier to notice patterns, infer rules, and organize new language knowledge, which boosts L2 development. That’s why having L1 proficiency before starting L2 acquisition best supports success.

Exposure to L2 without an L1 foundation doesn’t provide that necessary base for effective transfer, motivation alone isn’t enough, and simply being immersed in L2 classrooms misses the crucial cognitive-linguistic groundwork that the L1 foundation provides.