Abstract
The thesis investigates three problems in Mandarin phonology, including the prenuclear glides, the fricatives and the tone changes. Optimality Theory is used here, which assumes that the Universal Grammar (UG) consists of a set of constraints. The surface output form is selected by the ranking of constraints. Language differences are attributed to the different rankings of constraints. The constraint rankings take place of the derivational stages. The first problem is the tone changes of three kinds of disyllabic reduplicants, such as xAw2 xAwN, þje3 þjeN, xAw3 xAwrH. The tone of the first syllable of the first reduplicant has to change whereas the two latters haveto maintain the lexical tone. The tone of the second syllable of the first reduplicant changes optinally, whereas the latters must change. OT proposes the correspondence relations among Input-Base, Input-RED, Base-RED, to explore the tone changes. However, there are problems in case of analying in Lexical Phonology or Autosegmental Phonology. The second problem is the status of the prenuclear glides /j,w,ç/. The behaviour of the prenuvclear glides is different. The highly ranked constraints *COMPLEX, *ONSET, require the glides to occur in the onset position, where no other consonants available there. The constraints would be reranked as the child grows up. The markedness constraints demote under the faithfulness constraints finally. From the constraint rankings the prenuclear glides in adult forms are dominated either by the onset or the rhyme. The third problem is the acquisition of Mandarin fricatives. Affricates, stopsand aspirated affricates are the replaced sound for the fricatives during the developing stages. The rankings of the relevant constraints such as MAX(cont), DEP(-cont),*+cont are reajsuted. It is found that the demotion and promotion of the constraints are probable. It is better to use the MAX constraint than the IDENT ones. Not only the three problems mentioned above could be analyzed in OT, but also OT provides the explanations by constraint rankings instead of rule derivations for such as loanword phonology.