Not all learners benefit equally from the teaching environment that teachers, departments and institutions provide for them. Individual learners progress differently, depending on a variety of factors that influence their experiences and achievements as language learners. Individual variation includes psychological factors, such as cognitive and affective abilities and styles, which are traditionally classified as individual differences (IDs). In addition, learners also differ regarding the knowledge and previous learning experiences that they bring to the process. Languages they have previously acquired or learned in particular affect their ab initio language learning. Although the exact effects are still unclear, these cross-linguistic influences