Semantics is the study of meaning in language. It asks how words, phrases, and sentences map onto concepts, objects, and situations in the world. The word “dog” refers to a certain class of animals; the sentence “The dog chased the cat” describes a particular kind of event. Semantics seeks the rules and representations that make these mappings possible.

At the word level, lexical semantics examines sense, reference, and relations such as synonymy and antonymy. At the sentence level, compositional semantics investigates how the meanings of parts combine according to syntactic structure. Pragmatics, sometimes distinguished from semantics, adds the contribution of context and speaker intention.

Children acquire semantic knowledge gradually. Early word meanings are often overextended or underextended. Adult speakers continue to refine and expand the semantic network throughout life. Disorders such as aphasia can selectively impair semantic processing while leaving other language components relatively intact.

• Meaning of words and sentences
• Lexical and compositional levels
• Relations among meanings
• Distinct from syntax and pragmatics

Without semantics, language would be an empty formal system incapable of communication.