It is generally recognized that not only do linguistic abilities affect performance in mathematics but that mathematics itself is a specialized language. Monroe and Engelhart (1931) summarized some of the earlier research on the relationship of reading ability to problem solving. More recently, the writer (Aiken, 1971b) briefly reviewed research concerned with verbal factors in mathematics learning and teaching conducted during the past four decades. As one reader of that paper pointed out, however, a review of studies pertaining to the effects of all language factors would be more useful. This is the intention of the present paper. Although many of these studies involve only a few variables, are not clearly tied to other investigations, and frequently pose more questions than they answer, a number of implications and suggestions for further research are embedded in them.