Using a study of 30 Danish freshman college students' vocabularies as a springboard, this paper explores and discusses a number of current assumptions about vocabularies in the mother tongue and in foreign language pedagogics. The paper contends that it is logical to assume that vocabularies in reading are fluid and depend on the text read, on the reading strategies employed, and on the words the readers feel they know. The paper argues that a reader's vocabulary is part of the process of reading: it is a function of the text and its contents, of the reader's reading strategies, and of the reader's more or less stable "word knowledge," with a constant interplay between these factors. This implies that a deliberate teaching of reading strategies in addition to other methods would be pedagogically sound. The major portion of the paper discusses in detail how current assumptions fall short of explaining the findings in the original study which led to the reading strategies theory. One illustration, two charts, two tables of data and two notes are included, and 22 references and two appendixes are attached. (MS)