1 / 14

Linguistic Essentials

Linguistic Essentials. Parts of Speech and Morphology. Parts of Speech correspond to syntactic or grammatical categories such as noun, verb, adjectives and prepositions .

enid
Download Presentation

Linguistic Essentials

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Linguistic Essentials

  2. Parts of Speech and Morphology • Parts of Speech correspond to syntactic or grammatical categories such as noun, verb, adjectives and prepositions. • Word categories are systematically related by morphological processes such as the formation of plural form from the singular form.

  3. Parts of Speech • Nouns, verbs, adjectives • Determiners • Adverbs She ran very quickly; She often travels to Vegas; She started off impressively. • Preposition She looked up the tree • Particles She looked up the number • Conjunctions, complementizer Funny but stupid She is afraid that ….

  4. S --> NP VP NP --> DT NNS | DT NN | NP PP VP --> VP PP | VBD | VBD NP P --> IN NP DT --> the NNS --> children | students | mountains VBD --> slept | ate | saw IN --> in | of NN --> cake Syntax or Phrase Structure: A simple context-free grammar The Grammar The Lexicon

  5. Syntax or Phrase Structure: A Parse Tree S NP VP AT NNS VBD NP The children ateAT NN the cake

  6. Local and Non-Local Dependencies • Dependencies may be local e.g., DT NNS • A non-local dependency is an instance in which two words can be syntactically dependent even though they occur far apart in a sentence (e.g., subject-verb agreement; wh-extraction). • Non-local phenomena are a challenge for certain statistical NLP approaches (e.g., n-grams) that model local dependencies.

  7. Semantic Roles • Most commonly, noun phrases are arguments of verbs. These arguments have semantic roles: the agent of an action, the patient and other roles such as the instrument or the goal.

  8. Subcategorization • Different verbs can relate different numbers of entities: transitive versus intransitive verbs. • Verbs are classified according to the type of complements they permit. This called subcategorization. • FrameNet combines semantic roles and subcategorization. Let’s look up “put.v”

  9. Attachment Ambiguity and Garden-Path Sentences • Attachment ambiguities occur with phrases that could have been generated by two different nodes in the parse tree. E.g.: The children ate the cake with a spoon. • Garden-Path sentences are sentences that lead you along a path that suddenly turns out not to work. E.g.: The horse raced past the barn fell.

  10. Semantics • Semantics is the study of the meaning of words, constructions, and utterances. • Semantics can be divided into two parts: lexical semantics and combination semantics. • Lexical semantics: hypernymy, hyponymy, antonymy, meronymy, holonymy, synonymy, homonymy, polysemy (no need to memorize!). • Compositionality: the meaning of the whole is built up from the meanings of its parts different from its parts. (More on the next slide…)

  11. Semantics:Idea of Strict Compositionality • The overall meaning of a phrase or sentence derives from the meanings of the constituent parts and the particular grammatical ways in which the parts are put together. • Let’s consider examples using the context free grammar we saw earlier …

  12. S --> NP VP NP --> DT NNS | DT NN | NP PP VP --> VP PP | VBD | VBD NP P --> IN NP DT --> the NNS --> children | students | mountains VBD --> slept | ate | saw IN --> in | of NN --> cake Syntax or Phrase Structure: A simple context-free grammar The Grammar The Lexicon

  13. While the constituent parts of a sentence and its grammatical structure are important for determining its meaning, strict compositionality often breaks down • Idioms are one area of language where meanings are not compositional; “to be at a crossroads” means “facing a decision or choice”

  14. Pragmatics • Pragmatics is the area of studies that goes beyond the study of the meaning of a sentence and tries to explain what the speaker really is expressing. • Understand the scope of quantifiers, speech acts, discourse analysis, anaphoric relations.

More Related