Actant

An actant is the same as a dependent syntactic argument, i.e. a noun phrase (or other referential constituent) that is required by a valency of a predicate.

Comments

 * The term actant goes back to Tesnière (1959) and has been fairly common especially in European linguistics since the 1970s. However, the quasi-synonym argument is becoming more and more common.
 * There is a slight difference between the notions of actant and argument. I.e., in attributive phrases (derived as a result of adjectivization) the determined constituent is an argument of its modifier, but not an actant of it.


 * In Tesnière's terminology, actants are opposed to circumstants, i.e. optional modifiers of the clause.


 * The main subtypes of actants are subject (= first actant)and objects (non-first actants).
 * There is some difference between semantic actants and syntactic actants. E.g.:
 * (1) some syntactic actants, like "dummy subjects" (like it in Engl. It rains.), correspond to no semantic actant.
 * (2) some semantic actants, like "zero" object ('on what?') in Engl. It depends., correspond to no syntactic actant.

Reference

 * Tesnière, Lucien. 1959. Éléments de syntaxe structurale. Paris: Klincksieck.

Other languages

 * German Aktant
 * Russian актант