1 The experience which lies back of this article is as follows: 1. Use of a native language after preliminary lectures on another dialect by an ethnologist who spoke it, followed by intensive work with a literate English-speaking linguistic informant, and use of a Dictionary; ethnological work on an island where two natives spoke fluent English and three others some English. Samoa. 2. Use of a native language on which there was a brief published grammar, and a series of published texts, and followed by work with a linguistic informant who understood some English and spoke fluent pidgin; ethnological work in a community where about 25 per cent of the men spike pidgin, and a few small boys spoke some pidgin. Manus. 3. Complete non-use of the native language, and no use of interpreters, working entirely with English speaking informants, most of whom were women. Omaha Indians. 4. Use of a native language of which a very brief preliminary investigation of the grammar was available, followed by work with a linguistic informant who spoke plantation pidgin, and work in a community in which five adult men spoke pidgin. Arapesh. 5. Partial use of a native language on the basis of work with a linguistic informant who spoke good Rabaul pidgin; work in a community in which about 15 per cent of the men spoke some pidgin-all of them very young. Mundugumor. 6. Partial use of the native language on the basis of work with a linguistic informant who spoke Rabaul pidgin; work in a community where some two dozen of the very young men spoke pidgin English. Tchambuli.