The restriction of internally headed relative clauses to OV languages implies that these relative clauses are found in languages having left-branching rather than (in addition to) right-branching NP structure.
Standardized
IF there are internally headed relative clauses, THEN basic word order will be OV. IF basic word order is OV, THEN there will be left-branching. FROM WHICH FOLLOWS: IF there are internally headed relative clauses, THEN there will be left-branching NP structure.
1. In INTERNALLY HEADED relative clauses, the nominal which is understood as the head occurs, on the surface, in a position internal to the modifying clause. Downing (#679) calls such relative clauses ‘replacive’, Keenan (#1595) calls them ‘internal RelCs’, Gorbet (#1601) refers to them as to ‘headless relative clauses’ Gil (2000) and Cole himself refer to them as to ‘internally-headed’. 2. This statement is derived by transitivity from ##679, 1595 (internally headed relative clauses => OV order) and #920 (OV => left-branching).
1. In INTERNALLY HEADED relative clauses, the nominal which is understood as the head occurs, on the surface, in a position internal to the modifying clause. Downing (#679) calls such relative clauses ‘replacive’, Keenan (#1595) calls them ‘internal RelCs’, Gorbet (#1601) refers to them as to ‘headless relative clauses’ Gil (2000) and Cole himself refer to them as to ‘internally-headed’. 2. This statement is derived by transitivity from ##679, 1595 (internally headed relative clauses => OV order) and #920 (OV => left-branching).