Part-of-Speech

Also known as: POS, Word Class, Lexical Category

The grammatical category of a word — noun, verb, adjective, adverb, preposition, pronoun, conjunction, determiner, and so on. Part-of-speech labels are the basic output of part-of-speech tagging and a foundational input to many accessibility NLP pipelines: readability assessment, text simplification, screen-reader disambiguation of homographs, and voice-interface intent parsing all depend on accurate POS information. In readability research, POS distributions (notably the density of nouns and prepositions) are often more predictive of text difficulty than surface counts of syllables or sentence length.