A system for teaching advanced English as second language students how to use "a,""an," and "the" in writing is described. In deciding whether to use a definite or indefinite article, the student is taught to ask three questions about the context and nature of the noun: (1) has it been mentioned before in the composition, (2) is there anything definite right after the noun, and (3) is there only one in existence ( as in "the earth"). The noun requires a definite article if any of these questions is answered in the affirmative. If all of the questions are answered in the negative, the learner must then consider whether the noun in question is a count noun and whether it is singular. A singular count noun requires no article. A test of the questioning system on native speakers of English yielded disagreement on which article to use in some cases but demonstrated that context and prior knowledge make a difference in debatable areas. The system can help English as second language speakers to define their own context and to arrive at one of the correct uses of articles in each case. Sample exercises are appended. (RW)