转换生成语法的发展过程12-5（PPT61页)

转换生成语法的发展过程IntroductionTheIndependenceofGrammargrammaticalgrammatical+meaningfulTomlovesMary.grammtical,non-meaningfulColorlessgreenideassleepfuriously.ungrammaticalungrammatical,meaningfulWhichartistsdidyoufindworksbyinteresting.ungrammtical,non-meaningfulFuriouslysleepideasgreencolorless.ThefundamentalaiminlinguisticanalysisSeparatethegrammaticalsentencesfromtheungrammaticalsentences.Studythestructureofthegrammaticalsentences.Thegrammarofalanguage(L)willbeadevicethatgeneratesallofthegrammaticalsentencesofLandnoneoftheungrammaticalones.ThreemodelsforthestructureofalanguageFiniteStateGrammarPhraseStructureGrammarTransformational&GenerativeGrammarFiniteStateGrammarSupposewehaveamachine(thespeaker)–Thathasafinitenumberofdifferentinternalstates-aninitialstateafinalstate.Thatswitchesfromonestatetoanotherbyproducingasymbol.Thatbeginsintheinitialstate,runsthroughasequenceofstatesandendsinthefinalstate.Themancomes.Themencome.StateDiagramFiniteStateGrammarThecomecomesmanmenEachnodeinthediagramcorrespondstoastate.finalstateinitialstateLanguageproducedbysuchamachineiscalledafinitestatelanguage.Machinethatproducessuchalanguageiscalledafinitestategrammar(FSG).FSGisthesimplesttypeofgrammarwhich,withafiniteamountofapparatus,cangenerateaninfinitenumberofsentences.FiniteStateGrammarPropertiesofFiniteStateGrammarsSuchgrammarsallowtransitionfromonestatetoanother.Eachstaterepresentsthegrammaticalrestrictionsthatlimitthechoiceofthenextword.Machinesthatproducelanguagesinthismannerarealsoknownas“finitestateMarkovprocesses”.ProblemswithFSGs不能处理非连续出现的句子成分间的关系；Theoldmancomes.不能反应非相邻成分间的依存关系；Whatdoestheoldmanspeak?有限的意味着规则不能重复使用，会导致语法系统过于复杂。PhraseStructureGrammarItbuildsupphrasesoutofwordsandputthephrasestogetherintosentences.Thekindofstructuraldescriptionassignedbyaphrase-structuregrammaris,infact,animmediateconstituentanalysisofthesentence.Itassignstoeachsentencethatitgeneratesastructuraldescription.Itmakesuseofphrasestructurerules.AnexampleofaPhraseStructureGrammarThechildfoundthepuppy.AnexampleofaPSG(associatedwithconstituentanalysis):(1)S→NP+VP(2)NP→Det.+N(3)VP→Verb+NP(4)Det.→the,a,...(5)N.→child,puppy,...(6)V.→foundRepresentationusingaTreeDiagramSNPVPThechildDet.NtheVNPDet.NpuppyfoundInadequaciesofPSGAlthoughChomskyfoundphrase-structuregrammartobenecessary,hearguedthatthiswasnotsufficient.1.Itunder-generatesi.e.failstogenerateallthegrammaticalsentencesofthelanguage.Heburstintoaloudcryandlefttheroom.Themanwasbittenbythedog.Didthedogbitetheman?Wasthemanbittenbythedog?2.Itover-generates.Itblindlyallowsmanysentencesasgrammaticalwhichareinfactungrammatical.*TheboydiedBill.*Themenwouldputthebook.3.NotallcasesofambiguityareaccountedforbysuchGrammar.4.Toaccountforsuchphenomena,thegrammarmustalsoincludespecialtransformationalrulesthatgrabphrasesorpiecesofphrasesandmovethemaroundinspecifiedways.TransformationalandGenerativeGrammarAGenerativeGrammarisasetofformalrulesthatcangenerateaninfinitesetofsentencesthatconstitutethelanguageasawhole.Chomskyinsistedthatagrammar-Mustsystematicallydescribeallofthesentencesinalanguagethatanativespeakerwouldregardasgrammatical.Mustsortoutallofthepossiblegoodsentencesfromallofthepossiblebadones.Mustuseafinitesetofrules.Mustprovideawaytoaccountforourperceivedambiguityofcertainsentences.五个发展阶段PeriodModelAbbreviation1950sSyntacticStructure(ClassicalTheory)SS1960sStandardTheoryST1970sExtendedStandardTheoryEST1980sGovernmentandBindingGB1990sMinimalismProgrammeMPClassicalTheory（古典理论时期）时间：1957-1965代表作：SyntacticStructure（《句法结构》，1957）主要运作手段：结构转换转换的概念：同一个句子派生过程中的运作方式。转换运作的对象：现成的句子短语结构规则，负责生成现成的句子转换规则，负责改造现成的句子派生过程=生成+转换结构部分基础部分转换部分形态音位部分有音位值的句子ClassicalTheory（古典理论时期）词汇形态标志标点符号基本材料短语结构规则：改写规则基础结构转换规则经转换后的句子形态音位规则例句：TomlovesMary.结构部分基础部分转换部分形态音位部分有音位值的句子词汇:Tom,love,Mary形态标志:-s标点符号:.基本材料短语结构规则：改写规则基础结构:Tom-sloveMary转换规则经转换后的句子：Tomlove-sMary形态音位规则:love[lʌv]+-s[s]=[lʌvz]TomlovesMary.转换部分转换条件转换运作区域强制转换非强制转换：否定、疑问、被动狭义转换：单个句法结构内部广义转换：两个独立的句法结构之间古典理论存在的问题1.乔姆斯基的规则在生成规范句子的同时也生成不合格的句子。Eg:用S→NP+VP,VP→V+NP两条规则,我们可以得出Johndrinkswine.和WinedrinksJohn,这说明动词和名词之间有一定的选择限制.2.转换规则的力量过大，一个普通的句子可以随意地被改变，得不到任何限制。比如JohnmarriedMary和MarywasmarriedbyJohn的意思完全不同.StandardTheory（标准理论时期）时间：1965-1970代表作：AspectoftheTheoryofSyntax（《句法理论面面观》，1965）三大部分：基础部分：包括短语结构规则、词库和词汇搭配规则。语义部分：在深层结构层次上做出语义表达语音部分：对表层结构做出语音表达结构部分基础部分转换部分形态音位部分有音位值的句子词汇搭配规则——次范畴深层结构语义表达式表层结构语音形态表达式词汇插入规则投影规则音系规则词汇形态标志标点符号短语结构规则：改写规则转换规则形态音位规则词库标准理论时期短语结构规则词汇搭配规则深层结构词库语义表达式表层结构语音形态表达式词汇插入规则投影规则转换规则音系规则基础部分BaseComponentRe-writingRulesLexiconDeepStructureT-RulesSurfaceStructureSemanticComponentPhonologicalRepresentationPhonologicalComponentSemanticRepresentation标准理论时期标准理论的重大改进1.赋予语义以一定的地位。但转换具有独立性，转换只能改变句子的形式，而不允许改变意义.2.为了从规则中剔除生成类似winedrinksJohn的句子，标准理论有了选择性的限制来确保有生命的名词(John)出现在动词(drink)前，而无生命的名词(wine)则出现在动词后。3.这个时期，一些转换限制条件被提出，如孤岛条件（Ross，1967）.转换限制条件主要作用于转换过程，为了防止生成不合语法的句子。4.在改写规则里，符号S被放置于箭头的右边，如VPV+S和NPNP+S，这就意味着句子是可以嵌入的。通过这种方法，标准理论不仅可以概括简单的句子，而且可以概括复杂的句子。SSSSSSandSSS’NPVP5.规律得到正确的排列，并且在规则的运用上也有固定的次序。这样先用哪条规则后用哪条规则会有很大的不同。标准理论中存在的问题1)转换规则仍然权力太大,可以移动语言或删除语言片段,改变语类范畴,保持原意不变,还可以根据具体情