The phenomenon of "cross-code ambiguity" is offered as one explanation of the persistence of such Negro Nonstandard English (NNE) sentences as "The man he did it." In NNE the string "The man did it" is felt to be ambiguous, referring to either "The man who did it..." or, as in Standard English (SE), "The man did it." The use here of the pleonastic subject pronoun "he" removes the ambiguity by marking the non-relativization of the following verb phrases, a function stabilized by the regular deletion of the relative pronoun in this dialect. This process is analogous to the process in SE whereby the ambiguous string "I see the men do it" (either "I see they do it" or "I see them do it") is made unambiguous by using or deleting the clause marker "that" ("I see that the men do it"). Similarly, "It was a man under the bed" is ambiguous in NNE, reflecting the SE equivalents "There was a man under the bed" and "It was a man under the bed (who + VP)." It is important, therefore, for English teachers to realize that some of their cross-dialect communication problems with the NNE speakers are due to ignorance of ambiguous structures in the unfamiliar dialect. (JD)