An investigation of instances of phonological contact between Hungarian and American English concerns the perception and production of English interdental fricatives and English stops, in a representative selection of contexts, by native speakers of Hungarian. Implications of structural differences between the stop and fricative subsystems of the two languages are investigated through the administration of tests to Hungarians of limited proficiency in English. These tests are designed to ascertain the perceptual and productive interpretation by these subjects of a distinction present in English but lacking in Hungarian, namely, the tense-lax feature of the stops and interdentals, and of a phoneme pair--the interdentals--also present only in English. An extensive introductory chapter reviews the scope and investigative procedure of the study, prior and current research, and technical considerations. Consideration of perception, production, and identification in the research constitutes the major concern of the chapters on interdental fricatives and stops. The conclusion discusses contact theory, the factual findings, and theoretical implications of the study. A selected bibliography is included. (Author/RL)