The speech of two two-year-old Mandarin-speaking children was taped during free play in their homes. The following characteristics of their speech were discovered: (1) excellent, near full control of tones; (2) somewhat stricter word order than is found in adult speech (Mandarin is undergoing a word order shift from SVO to SOV); and (3) few coinages or use of the productive reduplicated forms in Mandarin, but greater than adult usage of morphological markings in the forms that were controlled. It seems that, despite the relative lack of morphological elaboration available in Chinese, the children found morphological markers easier to control than periphrastic forms involving adverbs or word order shifts and contrasts. In addition, all four children's preferences in aspectual relations marked seemed consistent enough to project a fuller generalized schedule for the emergence of aspectual relations over time. Further analysis indicates that aspectual distinctions are far more central to the children than temporal ones. A cognitive universal is proposed for early linguistic marking of changes of state (distinguishable from endings or results) to be commented on by the child in a variety of overextensions constrained relatively little by linguistic form. (Author/JB)