Most of the world’s population speaks a second language. Most of the words in a language are multimorphemic. Thus, the study of second language acquisition and processing offers a key window onto the nature of morphological representation and morphological ability. This chapter examines the acquisition, representation, and processing of inflected, derived, and compound words in a second language. Perspectives on second language variability and accuracy are surveyed, as well as perspectives on the path of development of morphological knowledge in second language learners. The chapter highlights how linguistic theory and experimentation can be used to (a) advance the understanding of morphological representation and processing, and (b) probe what underlies morphological ability. Finally, this chapter addresses the question of how an integrated bilingual mental lexicon can both maximize interlingual connectivity and accommodate the morphological differences that exist between languages.
