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Techniques of Grammatical Analysis Rajat Kumar Mohanty IIT Bombay.

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1 Techniques of Grammatical Analysis Rajat Kumar Mohanty IIT Bombay

2 What is Grammar? A theory of language A theory of competence of a native speaker An explicit model of competence A finite set of rules

3 What are the requirements? A model of competence –Should be able to generate an infinite set of grammatical sentences of the language –Should not generate any ungrammatical ones –Should be able to account for ambiguities –If two sentences are understood to have same meaning, the grammar should give the same structure for both at some level –If two sentences are understood to have different internal relationship, the grammar should assign different structural description

4 Techniques of Grammatical Analysis Two main devices –Breaking up a string Sequential Hierarchical Transformational –Labeling the constituents Morphological Categorial Functional A grammar may combine any of these devices for grammatical analysis.

5 Breaking upLabeling Grammatical Analysis Techniques Sequential Hierarchical Transformational Morphological Categorial Functional

6 Breaking up and Labeling –Sequential Breaking up Sequential Breaking up and Morphological labeling Sequential Breaking up and Categorial labeling Sequential Breaking up and Functional labeling –Hierarchical Breaking up Hierarchical Breaking up and Categorial Labeling Hierarchical Breaking up and Functional Labeling

7 Sequential Breaking up This device breaks up a sentence into a sequence of morphemes the + boy + s + kill + ed + the + un + happy + rat + s raam + ne + dande + se + saap + ko + maar + aa If a sentence is understood in two different ways, a grammar should give two corresponding descriptions –They + can + fish They are able to fish They put fish in cans

8 Sequential Breaking up and Morphological labeling the + boy + s + kill + ed + the + un + happy + rat + s word stem affix stem affix word affix stem stem affix word stem affix stem affix word affix stem stem affix raam + ne + dande + se + saap + ko + maar + aa word affix word affix word affix word affix word affix word affix word affix word affix After breaking up a sentence, we can give morphological labels to each units

9 Sequential Breaking up and Categorical Labeling This boy can solve the problem Det N Aux V Det N S

10 Sequential Breaking up and Categorical Labeling (…continued) They can fish Pronoun Aux Verb They can fish Pronoun Verb Noun

11 Sequential Breaking up and Categorical Labeling (…continued) They called her a taxi Pronoun Verb Pronoun Article Noun –They said she was a taxi –They called a taxi for her

12 Sequential Breaking up and Functional labeling They called her a taxi Subject Object Complement Verbal DO IO SubjectVerbalDO

13 Sequential Breaking up and Functional labeling (…continued) Old men and women HeadmodifierHeadcoordinator

14 Hierarchical Breaking up This device breaks up a sentence into its constituents at different hierarchies or levels Old men and women Old men and women Old men andwomen andmen Old

15 Hierarchical Breaking up and Categorial Labeling Poor John ran away ADJVADVN VPNP

16 Hierarchical Breaking up and Functional Labeling Immediate Constituent Analysis Construction types in terms of the function of the constituents: –Predication (subject + predicate) –Modification(modifier + head) –Complementation(verbal + complement) –Subordination (subordinator + dependent unit) –Coordination (independent unit + coordinator + independent unit)

17 In the morning, the sky looked much brighter Mod Modifier Head SubDU Mod Head Mod VerbalComplement PredicateSubject

18 Hierarchical Breaking up and Categorial /Functional Labeling Hierarchical Breaking up coupled with Categorial /Functional Labeling is a very powerful device But there are ambiguities which demand something more powerful

19 Love of God Someone loves God God loves someone Love of God Noun Phrase Prepositional Phrase Head DU Modifier Godoflove Sub- loveofGod

20 Generative Grammar A generative grammar –generates all the grammatical sentences of the language – rejects all the ungrammatical ones It is free to choose and combine any of the techniques of breaking up and labeling Depending upon what tools the grammar combines, we have different types of grammar

21 Types of Generative Grammar Finite State Model (sequential) Phrase Structure Model (sequential + hierarchical) Transformational Model (sequential + hierarchical + transformational)

22 Phrase Structure Model Inadequacies –Ambiguity –Paraphrase Relationship –Constructional Homonymy

23 Ambiguity If a sentence is understood to have two meanings, a grammar should give two corresponding structural descriptions PS grammar fails to meet this demand The shooting of the hunters –The hunter shot someone –Someone shot the hunters

24 NP the NDet PP PNP DetN shootingofthehunters

25 Paraphrase Relationship If two sentences are understood to have the same meaning, a grammar should give the same structural description for the two sentences at some level PS grammar fails to meet this demand Examples –The boy slapped the girl –The girl was slapped by the boy

26 S NP The NDet VP VNP DetN boyslappedthegirl

27 S NP The NDet VP VPP PNP girlslappedbyboywas AuxV the

28 Constructional Homonymy If two sentences are not understood the same way, a grammar should give two structural descriptions PS grammar cannot do this –The audience was asked to leave by the side-door –The audience was asked to leave by the chairman

29 S NP The NDet VP VInf. Phr audienceaskedto Side- door was AuxV leavebythe Inf. VP VPP PNP DetN

30 S NP The NDet VP VInf. Phr audienceaskedto Chairman was AuxV leavebythe Inf. VP VPP PNP DetN

31 Transformational Model If a generative grammar makes use of all the three -sequential -hierarchical and -transformational is called a Transformational grammar.

32 Transformational model PS model Makes use of PS rules exclusively PS rules generate surface structure Makes use of PS rules and transformational rules PS rules generate DS DS is converted into the surface structure by transformational rules

33 PS grammar Transformational grammar PS rules Surface Structure PS rules Transformation Deep Structure Surface Structure

34 Why wasn’t he punished? PS rules: S  NP – VP VP  V - NP – PP V  Aux – V Aux  (Tense)-(Modal)-(Perf)-(Prog) Tense  {pres/past} NP  (PreDet) - (Det) - (Ord) -(Quan) -(AP)-N Lexical substitution

35 S NP Someone VP VGPP pasthimfor some reason punish AuxV NP Tense

36 Why wasn’t he punished? (…continued) Transformations –Passivization –Agent deletion –Negation –Neg. Contraction –Wh- substitution –Interrogation –Wh- fronting –Affix switch

37 S NP He VP VGPP pastby for Some reason punish AuxV PP Passivization TensePass beensomeone PNP N

38 S He VP VGPP past for some reason punish AuxV Agent Deletion TensePass been

39 S NP He VP VGPP past for some reason punish AuxV Negation TensePass beennot

40 S NP He VP VGPP past for some reason punish AuxV Neg. Contraction TensePass enbe’not

41 S NP He VP VGWH past why punish AuxV Wh- Substitution TensePass enbe’not

42 S NP he VP VGWH past why punish Aux V Interrogative Tense enbe’not

43 S NP he VP VG pastpunish Aux V Wh-fronting Tense enbe’not WH why

44 S NP he VP VG past punish Aux V Affix switch Tense en be’not WH why was’notpunished

45 Suggested Readings Lyons, John Chomsky. Fontana, London. Palmer, Frank. Grammar Crystal, David. Linguistics

46 THANK YOU Q\A


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