The document discusses factors that influence language learning such as age, individual differences, learning styles, and motivation. It notes that age is a major factor in deciding what and how to teach as different ages have different needs, competencies, and cognitive skills. Teenagers tend to be more effective learners. Individual differences like learning preferences and personality traits also impact learning. Motivation can be intrinsic or extrinsic, and teachers should aim to nurture intrinsic motivation in students. Setting appropriate challenges and ensuring student success are important for maintaining motivation.