Contents: D.I. Slobin, Introduction. Part I:Ergative Languages. R.D. Van Valin, Jr., An Overview of Ergative Phenomena and Their Implications for Language Acquisition. N. Imedadze, K. Tuite, The Acquisition of Georgian. M. Fortescue, L.L. Olsen, The Acquisition of West Greenlandic. C. Pye, The Acquisition of K'iche Maya. E.L. Bavin, The Acquisition of Warlpiri. Part II:Non-Ergative Languages. M.S. Erbaugh, The Acquisition of Mandarin. K. Plunkett, S. Stromqvist, The Acquisition of Scandinavian Languages. K. Demuth, The Acquisition of Sesotho.