Types of relative clauses

Relative clauses are defined here as clauses that fulfill both of the following criteria:

  1. Taken as a whole, the clause functions as an attribute of the noun (N), answering the question What is the N like? or Which N?
  2. The structure contains a finite or nonfinite verb form distinct from the predicate of the main clause.[1]

A noun modified by a relative clause is considered the head of the NP. As the head, this noun may appear either within or outside the relative clause.[2]

This parameter describes the syntactic relationship of the relative clause to its head.


ExtRel: The head appears outside the relative clause. This is called an external relative clause.

IntRel: The head appears within the relative clause. This is called an internal relative clause.

CorrRel: The head appears both within the relative clause and as an anaphoric pronoun alongside the predicate of the main clause. This is called a correlative relative clause.

AdjnRel: The head obligatorily appears in the main clause, and the relative clause contains no anaphoric referent to the head, neither noun nor pronoun. This is called an adjoined relative clause.[3]

DblhdRel: The head obligatorily appears in both the main clause and the relative clause. (Alternatively, the main clause may contain a noun with a more general meaning, rather than the exact same noun.) This is called a double-headed relative clause.

When a language displays more than one type, two values can be listed. If one type is dominant, appearing in a greater variety of environments, a slash (/) can separate the two values, with the dominant value appearing first; if neither is dominant, they are listed with an ampersand (&) separating the two.


[1] If the relative clause is removed from the sentence, the main clause should be able to stand alone as a grammatical clause. The relative clause as defined here describes a broader category than in traditional usage of the term, as it has been expanded to include phrases containing a nonfinite, rather than finite, verb. For this reason, the underlined sections in the following English examples are equally considered to be relative clauses: The dog that is chasing the cat is barking; The dog chasing the cat is barking loudly.

[2] Consider the following examples from English: whichever dog barks and the dog that barks. The former is an internal relative clause, while the latter is an external relative clause.

[3] In addition to the entire clause being subordinate, a grammatical word or morpheme may also indicate that the phrase or clause is a relative clause.