L1 interference in bilingual language acquisition generally refers to the influence that the learner's L1 exerts over the acquisition of an L2. Habits have been formed during L1 acquisition will influence the L2 learning process, either facilitate or hinder L2 learning. The more similar L1 is with L2, the greater ease learners have with learning the L2 structures. In contrast, areas where L1 and L2 differ, the learners face much difficulty in learning because learners would use their L1 knowledge and experience to guide their L2 learning and responses.