Processability Theory (PT), a second language development theory, proposes a hierarchy of processing procedures that purportedly constrain interlanguage development. Although PT has been applied to a range of languages, little work has been done on Mandarin Chinese. The research in this book examines the development of noun phrase (NP) morphology and topic structures in interlanguage Chinese within the PT framework. The research proposes a five-stage hierarchy of NP and topic development in L2 Mandarin Chinese. Data was collected in New Zealand and China from learners with L1 English,...