Argument

The term argument is systematically ambiguous. In semantics, an argument is the entity about which a predication is made. In syntax, an argument is a constituent (noun phrase, adpositional phrase) that is required by another (predicative, argument-taking) constituent (verb, relational adjective, relational noun). In this second, syntactic sense, 'arguments' are also called 'argument terms'. Argument terms are said to be 'sub-categorized' by their governing predicates.

In Generative syntax, Argument is a phrase which is a referential expression and which is associated with a theta-role assigned by a lexical head.

Examples
In the following sentences, the italicized noun phrases (or adpositional phrases) are arguments (or argument terms):


 * Tasaku bought a ticket on Friday.
 * Please give my regards to your husband.
 * On the boat the passengers rely on the captain.

The NPs John and apples in (i)a are arguments of eat and the embedded sentence in (i)b is an argument of obvious. The phrase next week in (ii) is not an argument (of visit), and is assigned no theta-role.

(i) a  John eats apples b	 That you're in love is obvious

In Chomsky (1986a), arguments are construed as chains. Now we can say that in (iii) the theta-role of hit is assigned to the antecedent John, hence is associated with the argument (Johni, ti), which is a chain.

(iii)	Johni was hit ti

Comments
Arguments are typically contrasted with adjuncts, i.e. noun phrases or adpositional phrases that are not syntactically required, but serve to modify the clause or another constituent.

Semantics
in the formula P(a), a is called the argument of the predicate P. Generally, for a predicate with arity n, in P(a1,...,an), a1,...,an are called the arguments of P.

Subtypes

 * core argument
 * peripheral argument


 * external argument
 * internal argument

Synonyms

 * actant (Tesnière's term)
 * complement (though this term only refers to nonsubject arguments)

Polysemy
Argument also refers to
 * an argument (of a function) (in mathematical logic)

Link
Utrecht Lexicon of Linguistics

Other languages
German Argument French argument (fr) Russian аргумент