Intrinsic motivation is a motivation to learn that comes from an internal force such as interest in language learning or the desire for further personal development in general. It compares with extrinsic motivation, which is motivation from external pressures such as the need to speak English for work or because a parent has sent a learner to class.

Example
Often high level learners show a high degree of intrinsic motivation as they continue to study a language beyond any practical need.

In the classroom
Sometimes learners join a class because of extrinsic motivation and become motivated intrinsically as learning becomes enjoyable and rewarding. Getting feedback from the learners on the teaching and learning process through simple questionnaires about aspects of class can help a teacher identify what students find most useful and enjoyable.

Further links:

https://www.teachingenglish.org.uk/article/writing-young-learners

https://www.teachingenglish.org.uk/article/how-maximise-language-learning-senior-learners

See also:

https://www.teachingenglish.org.uk/article/extrinsic