The contraction phenomena in English (e.g. wanna contraction in the current paper) exhibit a situation, in which contraction is blocked by the presence of the movement trace. In the generative grammar framework (Chomsky, 1977; Chomsky and Lasnik, 1977, 1978; Jaeggli, 1980; Uriagereka, 1998), the presence of a trace between want and to is visible (e.g. Teddy is the man I want ..L to succeed), therefore, contraction over these two elements is not allowed. The source of the constraint is assumed to be from UG as it pertains to the structure of English. I am interested in observing whether the constraint is available to adult learners of English in the light of UG availability in second language acquisition. Korean learners of English were tested with a grammaticality judgment test on contraction constraint in possible and impossible situations. While some of them obeyed the constraint, many did not. The presence of many overgeneral speakers casts doubt on the general availability ofUG.