Traditional approaches to relative clause formation, both within traditional grammar and more recently within formal approaches, have relied heavily on the kind of relative clause constructions found in major European literary languages, in particular with case-marked relative pronouns. It is argued that this emphasis provides a skewed understanding of the phenomenon of relative clauses from a cross-linguistic perspective. Recent typological studies have served to redress this imbalance, and can be useful in the second-language acquisition of structurally different relative clause types.