In linguistics, an argument is an expression that helps complete the meaning of a predicate,[1] the latter referring in this context to a main verb and its auxiliaries.
[2] Most theories of syntax and semantics acknowledge arguments and adjuncts, although the terminology varies, and the distinction is generally believed to exist in all languages.
The area of grammar that explores the nature of predicates, their arguments, and adjuncts is called valency theory.
The basic analysis of the syntax and semantics of clauses relies heavily on the distinction between arguments and adjuncts.
The added phrases (in bold) are adjuncts; they provide additional information that is not necessary to complete the meaning of the predicate likes.
Psycholinguistic theories must explain how syntactic representations are built incrementally during sentence comprehension.
Argument status determines the cognitive mechanism in which a phrase will be attached to the developing syntactic representations of a sentence.
[citation needed] An important distinction acknowledges both syntactic and semantic arguments.
The predicate 'like' appears in various forms in these examples, which means that the syntactic functions of the arguments associated with Jack and Jill vary.
The equivalent sentence in English is ungrammatical without the required locative argument, as the examples involving put above demonstrate.
If the test constituent can appear after the combination which occurred/happened in a relative clause, it is an adjunct, not an argument, e.g.
The same diagnostic results in unacceptable relative clauses (and sentences) when the test constituent is an argument, e.g.
It incorrectly suggests, for instance, that modal adverbs (e.g. probably, certainly, maybe) and manner expressions (e.g. quickly, carefully, totally) are arguments.
Adjuncts can always be omitted from the phrase, clause, or sentence in which they appear without rendering the resulting expression unacceptable.
If it is altered somewhat, the relative clause diagnostic can also be used to distinguish arguments from adjuncts in noun phrases, e.g.
The optional adjuncts appear in one of a number of positions adjoined to a bar-projection of X or to XP.
The normal dependency edges (= non-arrows) identify the other constituents as arguments of their heads.
Thus Sam, a duck, and to his representative in congress are identified as arguments of the verbal predicate wanted to send.
There are many versions of argumentation that relate to this theory that include: conversational, mathematical, scientific, interpretive, legal, and political.
When one examines these areas of syntax, what one finds is that arguments consistently behave differently from adjuncts and that without the distinction, our ability to investigate and understand these phenomena would be seriously hindered.