In this chapter, we turn to Patty’s acquisition of some of the categories and features associated with nouns and noun phrases, particularly the features of number and definiteness. Descriptive data are presented on Patty’s use of possessive determiners, plural marking, and definite and indefinite articles. The feature of definiteness is examined in light of proposals that have been made regarding L1 transfer, especially White (2003a); definiteness is interesting in this respect because it is present in both English and Chinese, but expressed rather differently in each of those languages. In the last section of the chapter, I briefly discuss an interesting interaction between number marking and definiteness in Chinese that could hypothetically pose a transfer problem that Patty appears to have overcome (but we would need early-stage developmental data from other speakers to further explore this hypothesis).