1. Many individual difference factors can influence second language acquisition, including motivation, personality, beliefs, age, aptitude, and learner strategies. 2. Age makes a difference in SLA, with younger learners generally acquiring a second language faster and to a higher level of proficiency, especially in terms of phonology. Children are also able to achieve native-like fluency while adults are more likely to retain an accent. 3. Motivation also plays an important role, with integrative motivation that involves identifying with the target language culture linked to more successful SLA outcomes than instrumental motivation focused on practical benefits alone.