Part of speech

A part of speech (abbreviated form: PoS or POS) is a category of words (or, more generally, of lexical items) which have similar grammatical properties. Words that are assigned to the same part of speech generally display similar behavior in terms of syntax—they play similar roles within the grammatical structure of sentences—and sometimes in terms of morphology, in that they undergo inflection for similar properties. Commonly listed English parts of speech are noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, and sometimes numeral, article or determiner.

A part of speech – particularly in more modern classifications, which often make more precise distinctions than the traditional scheme does – may also be called a word class, lexical class, or lexical category, although the term lexical category refers in some contexts to a particular type of syntactic category, and may thus exclude parts of speech that are considered to be functional, such as pronouns. The term form class is also used, although this has various conflicting definitions. Word classes may be classified as open or closed: open classes (like nouns, verbs and adjectives) acquire new members constantly, while closed classes (such as pronouns and conjunctions) acquire new members infrequently, if at all.

Open class

Open class may refer to:

Steven Pinker

Steven Arthur "Steve" Pinker (born September 18, 1954) is a Canadian-born American cognitive scientist, psychologist, linguist, and popular science author. He is Johnstone Family Professor in the Department of Psychology at Harvard University, and is known for his advocacy of evolutionary psychology and the computational theory of mind.

Pinker's academic specializations are visual cognition and psycholinguistics. His experimental subjects include mental imagery, shape recognition, visual attention, children's language development, regular and irregular phenomena in language, the neural bases of words and grammar, and the psychology of cooperation and communication, including euphemism, innuendo, emotional expression, and common knowledge. He has written two technical books which proposed a general theory of language acquisition and applied it to children's learning of verbs. In particular, his work with Alan Prince published in 1989 critiqued the connectionist model of how children acquire the past tense of English verbs, arguing instead that children use default rules such as adding "-ed" to make regular forms, sometimes in error, but are obliged to learn irregular forms one by one.