Language is a system of spoken, written, or signed symbols and the rules for combining them to communicate meaning. It is a defining feature of human cognition and enables the transmission of knowledge across generations and cultures.

Language has several levels of structure: phonemes (basic sounds), morphemes (smallest meaningful units), syntax (rules for combining words), semantics (meaning), and pragmatics (social use). The study of language in psychology focuses on acquisition, comprehension, and production, and on the relationship between language and thought. Major debates include whether language is innate or learned and whether it shapes thought (the Sapir–Whorf hypothesis).

Levels of language

• Phonemes: basic speech sounds
• Morphemes: smallest meaningful units
• Syntax: grammatical rules
• Semantics: meaning
• Pragmatics: social use