THIS ANALYSIS OF UNDERLYING SYNTACTIC STRUCTURE IS BASED ON THE ASSUMPTION THAT THE PARTS OF SPEECH CALLED "VERBS" AND "ADJECTIVES" ARE TWO SUBCATEGORIES OF ONE MAJOR LEXICAL CATEGORY, "PREDICATE." FROM THIS ASSUMPTION, THE HYPOTHESIS IS ADVANCED THAT, IN LANGUAGES EXHIBITING THE COPULA, THE DEEP STRUCTURE OF SENTENCES CONTAINING PREDICATE ADJECTIVES IS IDENTICAL IN ALL SIGNIFICANT RESPECTS TO THAT OF SENTENCES WITH PREDICATES CONTAINING VERBS. THIS IMPLIES THE CLAIMS THAT "BE" IS A TRUE VERB AND THAT IT HAS A DEEP STRUCTURE SIMILAR TO SUCH LEXICAL ITEMS AS "TRY," AND "KNOW." SIX ARGUMENTS FROM WIDELY VARYING AREAS OF SYNTAX ARE USED TO SUPPORT THE HYPOTHESIS. THIS PAPER WAS PRESENTED AT THE WINTER MEETING OF THE LINGUISTIC SOCIETY OF AMERICA (NEW YORK, DECEMBER 28, 1966). (KL)