Apparently one can be a 'partially competent' native speaker of a language. It is clearly possible to have a native-like knowledge of one part of a language system and be lacking in another part. For example, one can have native-like phonology and syntax, but have holes in vocabulary and imperfect gender and case morphology, or satisfactory phonology and morphology but gaps in the syntax and vocabulary. It also appears that items heard in early childhood can persist in long-term memory and reappear in consciousness only decades later (Wayles Browne, p.c.). Also, there have been cases (none documented that I know of) where individuals appear to lack full flency in any language. For example, among the Yagua people of Northeastern Peru, we found that certain younger women who were partially culturally assimilated did not have full command of Spanish or Yagua. These women stood out in comparison to a) older culturally assimilated women who would speak Yagua fluently and some Spanish, b) non- assimilated women of all ages who spoke only Yagua fluently and c) all men, who would speak Yagua fluently and Spanish to varying degrees of fluency. In all situations that we were able to observe, including conversations with their husbands, these younger, assimilated women would not speak Yagua at all, and would only speak rudimentary Spanish, even though their husbands and others would address them in Yagua. It is hard to imagine that these women were fluent but 'latent' speakers of Yagua. (Thomas E. Payne p.c. 1995)