This paper presents two experiments in the acquisition of the nominal domain in English by Japanese and Spanish second language (L2) learners. The first experiment tests the L2 learners' ability to distinguish between count and mass nouns using a grammaticality judgement task and the second experiment tests learners on different types of definite (based on J. Hawkins's 1978 taxonomy) in count and mass contexts by means of a forced-choice elicitation task. The claim by Chierchia (1998a, b) is that there is a Nominal Mapping Parameter and the three languages discussed in this paper each have a different parametric value. The aim of the paper is to test Japanese and Spanish L2 learners of English to see whether they can reset the parameter to the English setting.