Principles and parameters is a framework within generative linguistics in which the syntax of a natural language is described in accordance with general principles (i.e. abstract rules or grammars) and specific parameters (i.e. markers, switches) that for particular languages are either turned on or off. For example, the distinction between whether a language is head-initial or head-final is regarded as a parameter which is either on or off for particular languages (i.e. English is head-initial, whereas Japanese is head-final).
Principles and parameters was largely formulated by the linguists Noam Chomsky and Howard Lasnik. Today, many linguists have adopted this framework, and it is considered the dominant form of mainstream generative linguistics.
Framework
The central idea of principles and parameters is that a person’s syntactic knowledge can be modelled with two formal mechanisms:
- A finite set of fundamental principles that are common to all languages; e.g., that a sentence must always have a subject, even if it is not overtly pronounced.
- A finite set of parameters that determine syntactic variability amongst languages; e.g., a binary parameter that determines whether or not the subject of a sentence must be overtly pronounced (this example is sometimes referred to as the Pro-drop parameter).
Within this framework, the goal of linguistics is to identify all of the principles and parameters that are universal to human language (called: Universal Grammar). As such, any attempt to explain the syntax of a particular language using a principle or parameter is cross-examined with the evidence available in other languages. This leads to continual refinement of the theoretical machinery of generative linguistics in an attempt to account for as much syntactic variation in human language as possible.
Language acquisition
The Principles and Parameters approach is the postulated answer to Plato’s Problem: how can a children with different linguistic environments arrive at an accurate grammar that exhibits universal and non-obvious similarities, relatively rapidly, and with finite input. According to this framework, principles and parameters are part of a genetically innate universal grammar (UG) which all humans possess, barring any genetic disorders. As such, principles and parameters do not need to be learned by exposure to language. Rather, exposure to language merely triggers the parameters to adopt the correct setting. The problem is simplified considerably if children are innately equipped with mental apparatus that reduces and in a sense directs the search space amongst possible grammars. The P&P approach is an attempt to provide a precise and testable characterization of this innate endowment which consists of universal, language-specific “Principles” and universal, binary “Parameters” that can be set in various ways. The interaction of the principles and the parameter settings produces all known languages while excluding non-natural languages.