IN ANALYZING WAYS BY WHICH VARIOUS LANGUAGES SIGNAL THE RELATIVE IMPORTANCE OF ELEMENTS IN A SENTENCE, ONE APPROACH (THAT OF TRANSFORMATION THEORY) IS TO RELATE EMPHASIS TO A TOPIC-COMMENT RELATIONSHIP. A COMPARATIVE ANALYSIS OF SEVERAL ENGLISH, TURKISH, AND JAPANESE SENTENCES THAT TAKE DIFFERENT PATTERNS OF EMPHASIS SUGGESTS THAT IN EACH CASE THE SPEAKER MUST CHOOSE WHICH ELEMENT IS THE TOPIC AND WHICH IS A COMMENT ON THE TOPIC. THIS CHOICE OF TOPIC-COMMENT STRUCTURE IS COMMON TO MANY LANGUAGES, AND IN SOME LANGUAGES THE SIGNALS OF THESE RELATIONSHIPS ARE AN IMPORTANT PART OF SYNTACTIC STRUCTURE. FOR EXAMPLE, THIS RELATIONSHIP IS SIGNALED IN ENGLISH BY RELATIVE STRESS, IN TURKISH BY WORD ORDER, AND IN JAPANESE BY SEPARATE MORPHEMES. OF THE SEVERAL WAYS OF ANALYZING THIS PHENOMENON, ONE (THE TAGMEMIC APPROACH) IS TO ALLOW THE DEEP STRUCTURE TO DEVELOP BOTH A TOPIC-COMMENT STRUCTURE AND AN INDEPENDENT PHRASE STRUCTURE. ALTHOUGH A SENTENCE MAY HAVE IDENTICAL TOPIC-COMMENT STRUCTURE AND PHRASE STRUCTURE MARKERS, A NUMBER OF UNIQUE COMPOSITE DEEP STRUCTURES MAY RESULT FROM MAPPING THE PHRASE STRUCTURE ONTO THE TOPIC-COMMENT STRUCTURE IN DIFFERENT WAYS. THIS PAPER WAS PRESENTED AT THE UNIVERSITY OF KENTUCKY FOREIGN LANGUAGE CONFERENCE (20TH, APRIL 29, 1967). (JD)