The English wh-cleft constructions, which consist of three parts, i.e. precopular wh-cleft clause, copula, and postcopular XP, show a peculiar behavior in number concord between the copula and the subject. The copula does not always appear to agree with the singular clausal subject, nor just with the postcopular XP. The copula is predominantly singular, but not always. Also, it can be plural before a plural NP, but not always. To explain this puzzling number concord phenomenon, we argue that the copula disjunctively agrees with the missing element within the precopular clause and the postcopular XP, and that this peculiar characteristic is attributed to the lexical properties of whatWH-CLEFT and beWH-CLEFT. Such a lexical specification-based treatment of number concord conforms to the lexicalist tradition of HPSG. (Chosun College of Science and Technology)