Diagnosing L2 development

This chapter introduces one of the key applications of Processability Theory. Diagnosing L2 development is equally important for SLA research and for language teaching. We will provide an overview of profile analyses and describe Rapid Profile, a diagnostic tool based on PT, offers a quick, valid and reliable, method of diagnosing interlanguage development. Key aspects in this chapter focus on (a) how to elicit speech samples and (b) how to use Rapid Profile.