This paper explores the linguistic specificity of English and Korean by comparing the formal realizations of specificity. The indefinite articles in English and zero articles in Korean are argued not to indicate the specificity features of the noun phrase[NP] concerned, with these features dependent partially on the contexts of the sentences and partly on additional lexical markers and word orderings of the arguments under the principle of communicative dynamism. Secondly, the two aspects of specificity effects are compared between the two languages. The first effect concerns the gradience of specificity when supplementary elements like certain/specific in English and etten/-ul in Korean are added to noun phrases. The supplementary elements in English ensure the specificity of the NPs, while these elements in Korean increase the probability of specificity, but do not guarantee it. The second effect is that the notion of specificity serves as a constraint on movement and co-reference. In English the specificity constraint for movement applies to the wh-movement and complex NP constraint for relativization, while it does not apply in the Korean language. It is argued that the specificity requirements for co-reference applies to long-distance co-reference of personal pronouns in English, while they apply to the reflexive pronoun caki and casin distinction in Korean.