This study investigated the age at which monolingual children can understand that different languages are different conventional systems of communication. In particular, we investigated when children can suspend using the mutual exclusivity (ME) assumption that a label solely refers to one category when interpreting novel words from foreign languages. Methods: Two-year-olds (n = 16) and 3-year-olds (n = 16) participated in the procedure, which consisted of three blocks. In the first block, a Korean speaker taught the children a novel word, muppi, referring to a novel object. The children were presented with two objects, muppi and another novel object. The Korean speaker then asked the children to find a referent of either muppi or the other novel Korean label, kkati. In the second block, a foreign language (either English or Spanish) speaker asked children to find the object for a foreign novel word, sefo, presenting two objects: muppi and the third novel object, which had not been presented before. The procedure of the third block was identical to that of the first block. Results: Three-year-olds exploited the ME assumption when interpreting a Korean novel word but not when interpreting a foreign novel word. In contrast, 2-year-old children did not use the ME assumption when interpreting native and foreign words. Conclusion:Children acquire an understanding that native and foreign languages have different words for an object at least by 3 years of age.

Objectives:The purpose of this study was to investigate the mediating effect of mother's task supportive behaviors on the relations between maternal parenting anxiety and preschoolers' selfdetermination. Methods: Data were analyzed using frequency, mean, standard deviation, and multiple regression analysis with SPSS 25.0 program, PROCESS macro by Hayes (2013) was used to analyze the mediated effects. Results: First, maternal parenting anxiety was negatively correlated to maternal cognitive scaffolding, maternal emotional scaffolding, and preschoolers' self-determination. However, it was positively correlated to maternal directive-controlling behaviors. Second, when controlling family income, maternal parenting anxiety and directive-controlling behaviors had a significant negative effect on preschooler's self-determination. Moreover, maternal emotional scaffolding had a significant positive effect on preschooler's self-determination. Lastly, the effects of maternal parenting anxiety on preschoolers' selfdetermination were partially mediated by maternal emotional scaffolding and maternal directivecontrolling behaviors. Conclusion:This study confirms that maternal parenting anxiety and directive-controlling behaviors have a negative influence on preschooler's self-determination. Additionally, it is important to provide compassionate support such as praise and encouragement to foster the development of preschooler's self-determination.