This paper discusses empirical findings from the first language acquisition of Mandarin Chinese suggesting that certain properties of the logical form of natural language are not learned from experience. These unlearnable properties appear to manifest themselves in the child's linguistic knowledge as soon as prerequisite conditions are met. Because of the inherent difficulties in the developmental study of quantification, the child language data reported does not confirm the innateness of the logical form properties at issue in a direct way. The evidence, however, is indicative of early acquisition of these linguistic properties, which are undetermined by the data the child is exposed to. The study is intended as a contribution to the study of linguistic universals. It was conceived on the assumptions of generative grammar and begins by placing itself in the broader context of the Chomskyan theory of linguistic universals. (Author/JL)