TWO OF THE MAJOR GRAMMATICAL PROBLEMS MUCH STUDIED BY MANDARIN GRAMMARIANS IN THE PAST DECADE ARE THE EXISTENCE OF PARTS OF SPEECH AND THE CONTROVERSY OVER THE IDENTIFICATION OF SUBJECT AND OBJECT IN SENTENCES. THE GOAL OF THIS STUDY IS TO DEAL WITH A VARIETY OF PROBLEMS IN CONNECTION WITH THE NOTIONS OF SUBJECT AND OBJECT IN MANDARIN CHINESE WITHIN THE GENERAL FRAMEWORK OF TRANSFORMATIONAL THEORY. A BRIEF SURVEY OF THREE TRADITIONAL APPROACHES TO THE SUBJECT-OBJECT PROBLEM IS MADE, AND THESE APPROACHES ARE FOUND TO BE DEFECTIVE MAINLY IN FAILING TO MAKE THE BASIC DISTINCTION BETWEEN DEEP STRUCTURE AND SURFACE STRUCTURE, WHICH IS IMPORTANT IN DEALING WITH GRAMMATICAL RELATIONS LIKE SUBJECT-VERB AND VERB-OBJECT. IT IS FOUND THAT MANDARIN HAS A RELATIVELY FREER WORD ORDERING THAN HAS BEEN ASSUMED. SETS OF SYNTACTICALLY RELATED SENTENCES WITH THE SAME UNDERLYING REPRESENTATION ABOUND IN THE LANGUAGE. SUBJECT DELETION AND OBJECT TRANSPOSITION ARE FOUND TO BE COMMON PHENOMENA. SUCH TRANSFORMATIONS ARE SHOWN TO BE CONNECTED WITH LOCATIVE PHRASE FRONTING OR WITH "BA" AND "BEI" TRANSFORMATIONS. (IT)