This book addresses the issue of fossilization in relation to a key question in SLA research, which is: why are learners, adults in particular, unable to develop the level of competence they have aspired to in spite of continuous and sustained exposure to the target language, adequate motivation to learn, and sufficient opportunity to practice?This book is a systematic attempt to address the issue of fossilization in relation to a fundamental question in second language acquisition research, which is: why are learners, adults in particular, unable to develop the level of competence they have aspired to in spite of continuous and sustained exposure to the target language, adequate motivation to learn, and sufficient opportunity to practice?ZhaoHong Han is Associate Professor of Linguistics and Education at Teachers College, Columbia University. Her research interests are in issues of second language learnability, ??teachability, and fossilization. Her research has appeared in journals such as Applied Linguistics, International Journal of Bilingual Education and Bilingualism, Language Teaching Research, and TESOL Quarterly.