JNTU B.Tech III NATURAL LANGUAGE PROCESSING Previous Question Paper (January/February - 2023 - R18)

An allomorph is a variant form of a single morpheme that occurs in different phonetic or morphological environments. While the meaning and function of the morpheme remain constant, its physical realization changes based on its context. For example, the English plural suffix morpheme /-s/ appears as [s] in 'cats', [z] in 'dogs', and [ɪz] in 'buses', making [s], [z], and [ɪz] allomorphs of the same plural morpheme.

A lexeme is the fundamental unit of lexical meaning in a language, representing the abstract entity that underlies all the inflected forms of a single word. For example, the forms "run," "runs," "ran," and "running" all belong to the same lexeme, typically represented by its lemma or dictionary form, "run."

Lexemes are generally categorized into two main groups:

• Open-class lexemes (Content words): These carry the primary semantic content of a sentence and are an open set, meaning new words are frequently added. Examples include nouns, verbs, adjectives, and adverbs.
• Closed-class lexemes (Function words): These provide grammatical structure and relationships between words. This is a fixed set that rarely changes. Examples include prepositions, conjunctions, determiners, and pronouns.