(By Matthew S. Dryer): "Map 90A shows the order of relative clause and noun. A construction is considered a relative clause for the purposes of this map if it is a clause which, either alone or in combination with a noun, denotes something and if the thing denoted has a semantic role within the relative clause. If there is a noun inside or outside the relative clause that denotes the thing also denoted by the clause, that noun will be referred to as the head of the relative clause. Headless relative clauses (like English what I bought at the store ) are not relevant to this map. ❡
The two basic types shown on Map 90A are languages in which the relative clause follows the noun, and languages in which the relative clause precedes the noun...❡
The relative clauses illustrated in (1) and (2) occur with heads outside the relative clause; these can be referred to as externally-headed relative clauses. In some languages, the head is inside the relative clause; these can be called internally-headed relative clauses. These are illustrated by the examples in (3) from Mesa Grande Diegueño (Yuman; southern California and northwest Mexico); the fact that the head is inside the relative clause is clearest in (3a), in which the head (gaat ‘cat’) occurs between the subject and verb of the relative clause.❡
The fourth type shown on the map is correlative relative clauses... Correlative clauses are strictly speaking a subtype of internally-headed relative clauses in that the head noun occurs inside the clause, but they differ from those coded here as internally-headed in that the relative clause is outside the main clause and is connected anaphorically to a noun phrase in the main clause that corresponds to the head noun in the English translations. ❡
The fifth type shown on the map consists of languages with adjoined relative clauses. As with the preceding type, adjoined relative clauses are outside the main clause; they do not form a constituent with the head noun, which is in the main clause, and they may be separated from it. However, unlike correlative clauses, the head occurs in the main clause rather than in the relative clause..."