Download presentation
Presentation is loading. Please wait.
Published byAbner Henry Modified over 9 years ago
1
Sanjukta Ghosh Department of Linguistics Banaras Hindu University
2
There are different grammatical theories available for analyzing natural languages. Some of them are Principles and Parameters (P&P) theory in its two versions (GB and Minimalism), GPSG and its latest modified version HPSG, LFG, TAG and Paninian model. Any of these theories can be used for developing a parser for NLP.
3
In Computer science and linguistics parsing is the process of analyzing a sequence of tokens to determine its grammatical structure with respect to a given formal grammar. The structure of the language and the features of the grammar formalism together are responsible for what kind of formal theory should be taken for analysis of the language.
4
If a grammar analyzes a sentence into different levels of derivation to reach to the actual surface structure, it is called a derivational grammar. E.g. Chomsky’s Government and Binding (GB) grammar formalism. If only the surface form of the sentence is represented by some grammar formalism ignoring any kind of derivation to reach that form it is called a representational grammar. E.g HPSG, LFG, Paninian Dependency model
5
The categorical constituent structure of sentences can be represented in the form of a Phrase Marker. What do phrase markers consist of? structure of Phrase Markers: HEADS, SPECIFIERS and COMPLEMENTS
6
THREE LEVELS OF SYNTACTIC CATEGORIES PHRASAL OR PHRASE PROJECTED FROM HEAD X (NP=N ) INTERMEDIATE OR LEVEL PROJECTED FROM THE HEAD X (N) LEXICAL OR LEVEL OF HEAD WORDS X (N) X -THEORY ABSTRACTS AWAY FROM PARTICULARS OF ONE SYNTACTIC CATEGORY OR ANOTHER AND GIVES A LANGUAGE-WIDE TEMPLATE FOR CHARACTERIZING SYNTACTIC STRUCTURE. IT IS A MOVE FROM LANGUAGE-SPECIFIC GRAMMAR TO UNIVERSAL GRAMMAR.
7
THE HEAD OF A LINGUISTIC UNIT IS THAT PART OF THE UNIT THAT GIVES ITS ESSENTIAL CHARACTER. N IS THE HEAD OF THE NP - ONE CAN REPLACE A PHRASE BY ITS HEAD. THEY CAN BE LEXICAL OR FUNCTIONAL. LEXICAL HEADS : N, A, P AND V FUNCTIONAL HEADS: COMPLEMENTIZER, INFL, DET COMPLEMENT AND ADJUNCT ARE NOT LEXICAL OR PHRASAL CATEGORIES, THEY ARE FUNCTIONAL CATEGORIES.
8
A HEAD TAKES A PHRASAL CATEGORY AS ITS COMPLEMENT. COMPLEMENTS ARE DAUGHTERS OF X AND SISTER OF SOME X CATEGORY. DIRECT OBJECTS ARE THE COMPLEMENTS OF VERBS. X X X Y (HEAD) (COMPLEMENT)
9
Unergative construction 1. John smiled (a beautiful smile). Unaccusative construction 2. John arrived (*an unexpected arrival). a. Unergative verbs: subject is the specifier of vP b. Unaccusative verbs: the subject is the complement of vP
10
v NP(Sub) (SPECIFIER) v v NP (Direct Obj) (HEAD) (COMPLEMENT)
11
John sighed. John gave a sigh. These two sentences will have uniform phrase structure representation, in both the sentence the subject John is generated in the Spec of vP. Only difference is in the first sentence v is overt and in the second it is gave.
12
Indian languages have constructions like V-V, N-V and A-V which together act as a unit or predicate. vah pahUZc gayA. (V-V) usne merI madad kI. (N-V) tumne mujhe khuS kiyA. (A-V) The second element is called a light verb (makes a vP) and the subject is generated in the Specifier position of this vP.
13
Verbs with one complement The boy took a savage beating. The boy took the book.
14
John gave Mary flowers. vP NP(sub) v’ v VP1 NP (IO) V’ V VP2 V’ V NP(DO)
15
The child ate the food. baccene khAnA khAyA. The mother fed the child. mAZne bacceko khAnA khilAyA. (same structure as ditransitive) The mother got the aayah to feed the child. mAZne AyA se bacceko khAnA khilwAyA.
16
Raising to subject John seems to be happy. John is actually the subject of the embedded clause and is raised to the subject position of the matrix clause. Raising to Object John believes Mary to be happy. Mary is raised from the subject position of the embedded clause to he object position of the matrix clause.
17
Subject control I want to be happy. Ram promised Bharat to come back. Object control Ram persuaded Bharat to go back.
19
Non-finite participial constructions are common in Indian languages. vah nActe nActe calA gayA. nacte nacte is adjoined to the main clause. Mohan ne dauRte hue ghoRe ko dekhA. Depending on the interpretation, dauRte hue is either adjoined the main clause or a modifier of the NP ghoRe in a DP.
20
THANK YOU For any query san_subh@yahoo.com
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.