This research project was designed to explore whether Extramural English, self-regulation and goal self-concordance are factors that contribute to the prediction of L2 achievement. This preoccupation addresses an important gap in the field: to explore possible factors that influence L2 achievement. This project will design and implement an L2 English proficiency test at an upper-secondary school in Trondheim. The test will comprise five parts: reading, listening, writing, speaking and vocabulary. Participants’ scores in these tests will be used as the indicators of their L2 achievement. Further data will be collected from participants regarding the relevant constructs, and it will be measured whether these constructs statistically predict L2 achievement. This project will explore whether and how these constructs predict L2 achievement, and hence, could make it possible to generate some practical implications for several stakeholders, including teacher educators, teachers, future teachers, and students of English.