This article discusses currently unsolved problems in linguistics

Linguistics

Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....

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Some of the issues below are commonly recognized as unsolved problems; i.e., it is generally agreed that no solution is known. Others may be described as controversies; i.e., while there is no common agreement about the answer, there are established schools of thought that believe they have a correct answer.

Concepts

• Is there a universal definition of word
  Word
  In language, a word is the smallest free form that may be uttered in isolation with semantic or pragmatic content . This contrasts with a morpheme, which is the smallest unit of meaning but will not necessarily stand on its own...
  
  ?
• Is there a universal definition of sentence
  Sentence (linguistics)
  In the field of linguistics, a sentence is an expression in natural language, and often defined to indicate a grammatical unit consisting of one or more words that generally bear minimal syntactic relation to the words that precede or follow it...
  
  ?
• Are there any universal grammatical categories?
• Can the elements contained in words (morphemes) and the elements contained in sentences (syntactic constituents) be shown to follow the same principles?
• Is it possible to formally circumscribe languages from each other? That is to say, is it possible to draw a clear boundary between two closely related languages that appear to have a dialect continuum
  Dialect continuum
  A dialect continuum, or dialect area, was defined by Leonard Bloomfield as a range of dialects spoken across some geographical area that differ only slightly between neighboring areas, but as one travels in any direction, these differences accumulate such that speakers from opposite ends of the...
  
   between their respective standard forms (e.g. Occitan and Catalan
  Catalan language
  Catalan is a Romance language, the national and only official language of Andorra and a co-official language in the Spanish autonomous communities of Catalonia, the Balearic Islands and Valencian Community, where it is known as Valencian , as well as in the city of Alghero, on the Italian island...
  
  )?
• How does grammaticalization function?
• How do creole language
  Creole language
  A creole language, or simply a creole, is a stable natural language developed from the mixing of parent languages; creoles differ from pidgins in that they have been nativized by children as their primary language, making them have features of natural languages that are normally missing from...
  
  s emerge?

Languages

• Origin of language
  Origin of language
  The origin of language is the emergence of language in the human species. This is a highly controversial topic. Empirical evidence is so limited that many regard it as unsuitable for serious scholars. In 1866, the Linguistic Society of Paris went so far as to ban debates on the subject...
  
   is the major unsolved problem, despite centuries of interest in the topic.
• Unclassified languages (languages whose genetic affiliation has not been established, mostly due to lack of reliable data) comprise about 38 of the 6,000-7,000 languages spoken in the world. An additional 45 languages are classified as language isolate
  Language isolate
  A language isolate, in the absolute sense, is a natural language with no demonstrable genealogical relationship with other languages; that is, one that has not been demonstrated to descend from an ancestor common with any other language. They are in effect language families consisting of a single...
  
  s, with no demonstrable relationship to other languages.
• Undeciphered writing systems
  Undeciphered writing systems
  Many undeciphered writing systems date from several thousand years BC, though some more modern examples do exist.The term "writing systems" is used here loosely to refer to groups of glyphs which appear to have representational symbolic meaning, but which may include "systems" that are largely...
  
  

Psycholinguistics

• Language emergence:
  • Emergence of grammar
    Grammar
    In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...
    
    
• Language acquisition
  Language acquisition
  Language acquisition is the process by which humans acquire the capacity to perceive, produce and use words to understand and communicate. This capacity involves the picking up of diverse capacities including syntax, phonetics, and an extensive vocabulary. This language might be vocal as with...
  
  :
  • Controversy: infant language acquisition / first language acquisition. How are infants able to learn language? One line of debate is between two points of view: that of psychological nativism
    Psychological nativism
    In the field of psychology, nativism is the view that certain skills or abilities are 'native' or hard wired into the brain at birth. This is in contrast to empiricism, the 'blank slate' or tabula rasa view, which states that the brain has inborn capabilities for learning from the environment but...
    
    , i.e., the language ability is somehow "hardwired" in the human brain, and that of the "tabula rasa
    Tabula rasa
    Tabula rasa is the epistemological theory that individuals are born without built-in mental content and that their knowledge comes from experience and perception. Generally proponents of the tabula rasa thesis favour the "nurture" side of the nature versus nurture debate, when it comes to aspects...
    
    " or blank slate, i.e., language is acquired due to brain's interaction with environment. Another formulation of this controversy is "nature versus nurture".
  • Is the human ability to use syntax based on innate mental structures or is syntactic speech the function of intelligence and interaction with other humans? The question is closely related to those of language emergence and acquisition.
  • The language acquisition device
    Language acquisition device
    The Language Acquisition Device is a postulated "organ" of the brain that is supposed to function as a congenital device for learning symbolic language . First proposed by Noam Chomsky, the LAD concept is an instinctive mental capacity which enables an infant to acquire and produce language. It is...
    
    : How localized is language in the brain? Is there a particular area in the brain responsible for the development of language abilities or is it only partially localized?
  • What fundamental reasons explain why ultimate attainment in second language acquisition
    Second language acquisition
    Second-language acquisition or second-language learning is the process by which people learn a second language. Second-language acquisition is also the name of the scientific discipline devoted to studying that process...
    
     is typically some way short of the native speaker
    Native Speaker
    Native Speaker is Chang-Rae Lee’s first novel. In Native Speaker, he creates a man named Henry Park who tries to assimilate into American society and become a “native speaker.”-Plot summary:...
    
    's ability, with learners varying widely in performance?
  • Animals and language: How much language (e.g. syntax
    Syntax
    In linguistics, syntax is the study of the principles and rules for constructing phrases and sentences in natural languages....
    
    ) can animals be taught to use? How much of animal communication can be said to have the same properties as human language (e.g. syntax
    Syntax
    In linguistics, syntax is the study of the principles and rules for constructing phrases and sentences in natural languages....
    
    )?
• An overall issue: Can we design ethical psycholinguistic experiments to answer the questions above?

Translation

• What should the translator adhere to: fidelity or transparency?
• Is there an objective gauge for the quality of translation
  Translation
  Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...
  
  ?