List of unsolved problems in linguistics

This article discusses currently unsolved problems in linguistics.

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?
• Is there a universal definition of sentence?
• 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?
• How are domains for phonological processes related to syntactic structure? Do prosodic domains deviate from syntactic constituent structure?
• Is it possible to formally delineate languages from each other? That is to say, is it possible to use linguistic (rather than social) criteria to draw a clear boundary between two closely related languages with a dialect continuum between their respective standard forms (e.g. Occitan and Catalan)?
• How does grammaticalization function?
• How do creole languages emerge?

Languages

• Origin of language and origin of speech are major unsolved problems, despite centuries of interest in these topics.^[1][2][3][4]
• Unclassified languages (languages whose genetic affiliation has not been established, mostly due to lack of reliable data) make up about 38 of the 6,000-7,000 languages spoken in the world.^[5] An additional 45 languages are classified as language isolates, with no demonstrable relationship to other languages.^[5]
• Undeciphered writing systems

Psycholinguistics

• Language emergence:
  • Emergence of grammar^[6]
• Language acquisition:
  • 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, i.e., the language ability is somehow "hardwired" in the human brain, and that of the "tabula rasa" 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: 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 is typically some way short of the native speaker's ability, with learners varying widely in performance?
  • Animals and language: How much language (e.g. syntax) 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)?

Translation

• Is there an objective gauge for the quality of translation?^[7]

References