What is "interlanguage" in the context of bilingual language development?

Interlanguage refers to the linguistic state that arises when a bilingual individual is in the process of acquiring a second language. It often results in a blend of the two languages, leading to a unique linguistic system that incorporates elements from both. This phenomenon is particularly common among language learners as they experiment and attempt to bridge the gaps in their knowledge of the target language.

This unique form can manifest in various ways, such as the mixing of vocabulary and grammar rules or the development of new pronunciations influenced by both languages. Interlanguage is a natural part of the language learning process, reflecting the learner's evolving understanding and use of the language.

The other options, while related to aspects of language development, do not accurately capture the essence of interlanguage. For instance, a completely separate language would imply that there is no connection to the languages being learned, which contradicts the nature of interlanguage as an intermediary state. Learning through music may enhance language acquisition but does not define interlanguage. The ability to switch languages smoothly refers to code-switching, distinct from the transitional phase represented by interlanguage.