Language

A modern language (also known as a living language) is any human language that is currently in use as a native language.

The term is used in language education to distinguish between languages which are used for day-to-day communication (such as French and German) and dead classical languages such as Latin and Classical Chinese, which are studied for their cultural and linguistic value. For example, the Modern Language Association tracks student enrollments in Ancient Greek versus Modern Greek, or Biblical Hebrew versus Modern Hebrew, separately.

Self-reference is a concept that involves referring to oneself or one's own attributes, characteristics, or actions. It can occur in language, logic, mathematics, philosophy, and other fields.

In natural or formal languages, self-reference occurs when a sentence, idea or formula refers to itself. The reference may be expressed either directly—through some intermediate sentence or formula—or by means of some encoding.

Philology (from Ancient Greek φιλολογία (philología) 'love of word') is the study of language in oral and written historical sources. It is the intersection of textual criticism, literary criticism, history, and linguistics with strong ties to etymology. Philology is also defined as the study of literary texts and oral and written records, the establishment of their authenticity and their original form, and the determination of their meaning. A person who pursues this kind of study is known as a philologist. In older usage, especially British, philology is more general, covering comparative and historical linguistics.

Classical philology studies classical languages. Classical philology principally originated from the Library of Pergamum and the Library of Alexandria around the fourth century BC, and was continued by the Ancient Greeks and then the Romans throughout the Roman and Byzantine Empire. It was eventually resumed by European scholars of the Renaissance, where it was soon joined by philologies of other European (Romance, Germanic, Celtic, Slavic, etc.), Asian (Arabic, Persian, Sanskrit, Chinese, etc.), and African (Egyptian, etc.) languages. Indo-European studies involve the comparative philology of all Indo-European languages.

A vocabulary (also known as a lexicon) is a set of words, typically the set in a language or the set known to an individual. The word vocabulary originated from the Latin vocabulum, meaning "a word, name". It forms an essential component of language and communication, helping convey thoughts, ideas, emotions, and information. Vocabulary can be oral, written, or signed and can be categorized into two main types: active vocabulary (words one uses regularly) and passive vocabulary (words one recognizes but does not use often). An individual's vocabulary continually evolves through various methods, including direct instruction, independent reading, and natural language exposure, but it can also shrink due to forgetting, trauma, or disease. Furthermore, vocabulary is a significant focus of study across various disciplines, like linguistics, education, psychology, and artificial intelligence. Vocabulary is not limited to single words; it also encompasses multi-word units known as collocations, idioms, and other types of phraseology. Acquiring an adequate vocabulary is one of the largest challenges in learning a second language.

Linguistic purism or linguistic protectionism is a concept with two common meanings: one with respect to foreign languages and the other with respect to the internal variants of a language (dialects).The first meaning is the historical trend of the users of a language desiring to conserve intact the language's lexical structure of word families, in opposition to foreign influence which are considered 'impure'. The second meaning is the prescriptive practice of determining and recognizing one linguistic variety (dialect) as being purer or of intrinsically higher quality than other related varieties.

The perceived or actual decline identified by the purists may take the form of a change of vocabulary, syncretism of grammatical elements, or loanwords. The unwanted similarity is often with a neighboring language the speakers of which are culturally or politically dominant. The ideal may invoke logic, clarity, or the grammar of classic languages. It is often presented as a conservative measure, as a protection of a language from the encroachment of other languages or of the conservation of the national Volksgeist, but is often innovative in defining a new standard. It is sometimes part of governmental language policy that is enforced in various ways.

In the study of language, description or descriptive linguistics is the work of objectively analyzing and describing how language is actually used (or how it was used in the past) by a speech community.

All academic research in linguistics is descriptive; like all other scientific disciplines, it aims to describe reality, without the bias of preconceived ideas about how it ought to be. Modern descriptive linguistics is based on a structural approach to language, as exemplified in the work of Leonard Bloomfield and others. This type of linguistics utilizes different methods in order to describe a language such as basic data collection, and different types of elicitation methods.

The most commonly used language in the United States is English (specifically American English), which is the national language. While the U.S. Congress has never passed a law to make English the country's official language, a March 2025 executive order declared it to be. In addition, 32 U.S. states out of 50 and all five U.S. territories have laws that recognize English as an official language, with three states and most territories having adopted English plus one or more other official languages. Overall, 430 languages are spoken or signed by the population, of which 177 are indigenous to the U.S. or its territories, and accommodations for non-English-language speakers are sometimes made under various federal, state, and local laws.

The majority of the U.S. population (77%) speaks only English at home as of 2024, according to the American Community Survey (ACS) of the U.S. Census Bureau. The second most common language by far is Spanish, spoken by 13.9% of the population, followed by Chinese, spoken by around 1% of the population. Other languages spoken by over a million residents are Tagalog, Vietnamese, Arabic, French, Korean, and Russian. Only 8.4% of U.S. residents report that they speak English less than "very well".

In sociolinguistics, an accent is a way of pronouncing a language that is distinctive to a country, area, social class, or individual. An accent may be identified with the locality in which its speakers reside (a regional or geographical accent), the socioeconomic status of its speakers, their ethnicity (an ethnolect), their caste or social class (a social accent), or influence from their first language (a foreign accent).

Accents typically differ in quality of voice, pronunciation and distinction of vowels and consonants, stress, and prosody. Although grammar, semantics, vocabulary, and other language characteristics often vary concurrently with accent, the word "accent" may refer specifically to the differences in pronunciation, whereas the word "dialect" encompasses the broader set of linguistic differences. "Accent" is often a subset of "dialect".

Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning, instead of spoken words. Sign languages are expressed through manual articulation in combination with non-manual markers. Sign languages are full-fledged natural languages with their own grammar and lexicon. Sign languages are not universal and are usually not mutually intelligible, although there are similarities among different sign languages.

Wherever communities of people with hearing challenges or people who experience deafness exist, sign languages have developed as useful means of communication and form the core of local deaf cultures. Although signing is used primarily by the deaf and hard of hearing, it is also used by hearing individuals, such as those with deaf family members including children of deaf adults.

In linguistics, productivity is the degree to which speakers of a language use a particular grammatical process, especially in word formation. It compares grammatical processes that are in frequent use to less frequently used ones that tend towards lexicalization. Generally the test of productivity concerns identifying which grammatical forms would be used in the coining of new words: these will tend to only be converted to other forms using productive processes.