Interlanguage is a linguistic term that describes the evolving language system used by learners as they acquire a new language. It reflects a mix of elements from both the learner's native language and the target language, often resulting in unique grammatical structures and vocabulary choices. This transitional phase is a natural part of language learning, showcasing the learner's progress and understanding. As learners interact with the target language, their interlanguage may exhibit errors and inconsistencies. These features can include overgeneralization, where rules from the native language are incorrectly applied, and fossilization, where certain errors become fixed. Understanding interlanguage helps educators tailor their teaching methods to support language acquisition effectively.