Natural language
Natural language refers to any system of communication developed and used by human communities organically over time, without premeditated design, encompassing spoken, signed, and written forms such as English, Mandarin, or American Sign Language, in contrast to artificial languages like Esperanto or formal languages used in computing and logic.[1][2] These languages serve as primary tools for human expression, enabling the conveyance of complex ideas, emotions, and information through arbitrary symbols that lack inherent connections to their meanings.[3] A defining characteristic of natural languages is their productivity, allowing speakers to generate an unlimited array of novel sentences and meanings from a finite set of elements, a feature unique to human communication systems.[3] They also demonstrate duality of patterning, where basic meaningless units (such as phonemes in spoken languages or handshapes in sign languages) combine into larger meaningful structures (like morphemes and words), facilitating efficient encoding of information.[3] Additionally, natural languages exhibit displacement, permitting reference to events, objects, or concepts removed in time or space from the immediate context, which supports abstract thought and storytelling.[3] Other key properties include semanticity, where signals carry specific meanings, and cultural transmission, as languages are acquired socially rather than innately specified beyond general capacities.[4] As of 2025, there are 7,159 living natural languages spoken worldwide, of which approximately 44% face endangerment due to globalization and cultural shifts, with the highest concentrations of linguistic diversity found in regions such as Papua New Guinea and sub-Saharan Africa.[5][6] The scientific study of natural languages falls under linguistics, which investigates their phonology, syntax, semantics, and pragmatics to uncover universal patterns and variations among them.[7]Definition and Scope
Definition
Natural language refers to any language that develops organically through human interaction and use for communication purposes, emerging spontaneously from innate human capacities rather than through intentional design.[8] This includes spoken languages, such as those produced through vocalization, signed languages using manual gestures and visual-spatial elements, and written forms derived from these primary modes.[9] The organic development emphasizes that natural languages evolve over time within communities, adapting to social, cultural, and environmental needs without centralized planning.[10] Prominent examples of natural languages include English, a Germanic language spoken by over 1.5 billion people worldwide as of 2025;[11] Mandarin Chinese, a Sino-Tibetan language serving as the lingua franca for more than a billion speakers as of 2025;[11] and American Sign Language (ASL), a visual language used by Deaf communities in the United States and parts of Canada.[12] The term "natural language" in linguistics originated in the early 20th century, gaining prominence with the advent of structuralism and later computational approaches, to distinguish human-evolved systems from constructed or formal ones.[13] In contrast to artificial languages like Esperanto, natural languages are characterized by their unplanned, community-driven evolution.[14]Distinction from Other Languages
Natural languages differ fundamentally from formal languages, such as those in mathematical logics like predicate calculus, in their structure and purpose. Formal languages are artificially constructed with rigid syntax and semantics to eliminate ambiguity, enabling precise logical inference but restricting expressiveness to well-defined domains.[15] In contrast, natural languages tolerate and even rely on ambiguity to convey nuanced, context-rich meanings, allowing for greater flexibility in expressing human thought and experience.[2] This distinction arises because formal languages prioritize computability and determinism, often at the expense of the dynamic, interpretive qualities inherent to natural languages.[16] Constructed languages, such as Esperanto, represent another category of non-natural languages, deliberately engineered by individuals or groups for specific goals like international auxiliary communication. While Esperanto incorporates patterns inspired by natural languages to facilitate human learning and use, it remains planned and lacks the spontaneous development seen in natural tongues.[17] Purely artificial systems, like computer code, go further by eschewing human-centric design altogether, focusing instead on machine-readable instructions without the irregularity or cultural adaptation of natural languages.[18] Thus, constructed languages bridge human usability and intentionality but do not qualify as natural due to their top-down creation rather than bottom-up emergence.[17] Programming languages exemplify formal languages tailored for computational tasks, emphasizing strict syntax rules and unambiguous semantics to ensure predictable machine execution. Unlike natural languages, where meaning often depends on contextual, pragmatic, and cultural factors, programming languages derive interpretation solely from syntactic structure, prohibiting the variability that enables creative expression in human communication.[19] This syntax-driven approach makes programming languages efficient for automation but ill-suited for the open-ended, evolving discourse of natural languages.[19] The primary criteria demarcating natural languages from these alternatives are their organic evolution through intergenerational transmission, pervasive irregularities stemming from historical contingencies, and profound cultural embedding that shapes vocabulary, idioms, and usage norms.[2] These traits reflect natural languages' roots in human social interaction, as opposed to the deliberate, static design of formal and constructed systems.[17] For instance, while a natural language like English accumulates exceptions through centuries of use, formal languages enforce uniformity to avoid interpretive errors.[2]Properties and Features
Design Features
In the mid-20th century, linguist Charles F. Hockett proposed a set of design features to characterize the structure and function of human natural languages, aiming to identify properties that make them uniquely suited for communication and distinguish them from other signaling systems. These features, initially outlined in his 1960 paper and expanded in subsequent works, provide a framework for understanding the communicative uniqueness of natural languages. Hockett identified 16 key design features, which collectively highlight the flexibility, expressiveness, and adaptability of human language. The following table summarizes Hockett's 16 design features, along with brief explanations of each:| Feature | Explanation |
|---|---|
| Vocal-auditory channel | Language is transmitted through sounds produced by the vocal tract and received via the auditory system, freeing the hands for other tasks.[20] |
| Broadcast transmission and directional reception | Signals are emitted in all directions but can be directed toward specific receivers, allowing for one-to-many or targeted communication.[20] |
| Rapid fading | Spoken signals dissipate quickly after production, requiring immediate attention and preventing permanent storage in the environment.[20] |
| Interchangeability | Any individual can both send and receive messages of equal complexity, enabling full participation in linguistic exchange.[20] |
| Complete feedback | Speakers receive immediate auditory feedback on their own utterances, allowing self-monitoring and correction during speech.[20] |
| Specialization | The vocal apparatus is dedicated primarily to communication rather than serving other biological functions like ingestion.[20] |
| Semanticity | Signals carry meaning by associating arbitrary forms with specific referents or concepts in the world.[20] |
| Arbitrariness | The connection between a signal and its meaning is conventional, not iconic or based on physical resemblance (e.g., the word "dog" does not resemble a dog).[20] |
| Discreteness | Language is composed of distinct, combinable units (e.g., sounds, words) rather than continuous signals.[20] |
| Displacement | Speakers can refer to events, objects, or ideas not present in the immediate context, such as past experiences or hypothetical scenarios.[20] |
| Productivity (or openness) | A finite set of rules and elements allows for the creation of an infinite number of novel utterances, enabling speakers to express new ideas.[20] |
| Traditional transmission | Language is acquired through social learning and cultural transmission across generations, rather than being genetically hardwired.[20] |
| Duality of patterning | Meaningful units (morphemes) are built from meaningless smaller units (phonemes), which themselves follow combinatorial patterns.[20] |
| Prevarication | Language permits the expression of falsehoods, fiction, or meaningless strings, allowing for deception or creativity.[20] |
| Reflexiveness | Language can be used to discuss language itself, such as describing grammar or analyzing utterances.[20] |
| Learnability | Humans can acquire any natural language with sufficient exposure, demonstrating the system's accessibility to learners.[20] |