The present study adopted a cognitive linguistic framework--Talmy's (1985, 1991, 2000) typological classification of motion events--to investigate how second-language (L2) Chinese learners come to express motion events in a targetlike manner. Fifty-five U.S. university students and 20 native speakers of Chinese participated in the study. A controlled composition task and a picture-cued written task were administered to elicit learners' knowledge and degree of mastery of Chinese spatial morphemes, also known as directional complements (DCs). Analysis of learners' interlanguage data shows that the difficulties came from the syntactic complexity of the target DC patterns and from the typological features of Chinese as a serial-verb language. The dual functions of DCs as path satellites and as independent verbs posed considerable difficulty for the learners whose first language (L1), English, encodes path by means of satellites only. Based on the results, a developmental order of mastery of L2 Chinese DCs is proposed. The study illuminates areas of difficulty in adjusting to the L2 thinking-for-speaking patterns (Cadierno, 2004, 2008; Slobin, 1996a) that arise when differences in spatial categorization and in conventionalized ways of path encoding exist between the L1 and L2.