This thesis aims to examine the extent to which native languages (Ll) influence interlanguage development and whether there exis,ts a direct link between the suppliance of appropriate morphemes and the presence of their syntactic properties in interlanguage grammars. To answer these questions, this thesis investigates adult second language (L2) acquisition of Mandarin nominal phrases by Japanese and English learners. Four nominal prope1iies shared by Mandarin and Japanese are the classifier projection (ClP), the incompatibility of . \ . the numeral-classifier phrase with the plural marker, adjectival possessives and the co-occurrence of determinative elements, all of which differentiate these two languages from English. T.h is study involves 80 Japanese learners and 80 . English learners (placed at four proficiency levels) and 20 Mandarin native speakers as controls. Two data-collecting tasks are employed in this study: an acceptability judgment task for the four Mandarin nominal prope1iies and a � fill-in-the-blank task for. the semantic selection of Mandarin classifiers. Our results from the acceptability judgment task suggest that Ll transfer is not absolute in L2 Mandarin. More specifically, Japanese learners only transfer adjectival possessives, but not ClP and the co-occurrence of determinative elements, to their initial L2 Mandarin. This absence of Ll transfer of ClP and the co-occurrence of determinative . elements is likely to be due to the markedness in terms of the implicational universal. Intriguingly, it is found that ClP and its associated syntactic specifications are gradually developed in English and Japanese learners' L2 Mandarin. Initially, English and Japanese measure words are incorrectly used to accommodate classifiers, and then ClP is projected without any syntactic specifications. Subsequently, the syntactic specifications of ClP are gradually specified. However, the incompatibility of the numeral-classifier phrase with the plural marker is still underspecified in English and Japanese learners' advanced L2 Mandarin. Remarkably, our results from the fill-in-the-blank task demonstrate that English and Japanese learners' failure to use semantically appropriate Mandarin classifiers does not hinder the presence of ClP and its syntactic specifications in their L2 Mandarin, which suggests that there is no direct linl( between these two. Moreover, the rarity of the positive evidence is argued to play a crucial role in English and Japanese L2ers' acquisition of the co-occurrence of determinative elements, which highlights the importance of input frequency in L2 acquisition. It is also believed to be responsible for a discrepa~cy observed in English learners' acquisition of two adjectival possessive constructions in Mandarin. This dissertation is my own work and contains nothing which is the outcome of work done in collaboration with others, except specified in the text and Acknowledgements. The dissertation does not exceed the regulation length, including footnotes, references and appendices but excluding the bibliography.