Following a brief review of the literature on cognates, and a discussion of six arguments in favor of using cognates as a vocabulary acquisition device, a study is described which was designed to determine whether students were able to utilize English-French cognates in listening and reading comprehension in French. Seventy-four tenth grade students in three French classes participated in the study. One class was the control group, one class received training in the phonemic differences of English-French cognates, and one class was taught the spelling alternations on English-French cognates. The experiment was carried out over a period of six weeks. Results indicate that students can be taught the phonemic and spelling differences of English-French cognates in a relatively short time, and it is suggested that teachers use cognates in their French classes. A detailed description of the tests used is provided. (CLK)