Interrogatives, relatives and clefts are structures that have a common property: they may begin with a wh‐expression generally linked to an empty position in its clause. In generative approaches, this expression is assumed to have been moved from a clause internal position to a left peripheral position. The three structures differ, however, in their discourse properties, word order patterns and syntactic distribution. This chapter considers these structures, pointing out their general properties, and relevant differences between European Portuguese (EP) and Brazilian Portuguese (BP), and reviews theoretical approaches to them. Relative clauses do not differ substantially in the two varieties of Portuguese, although non‐standard strategies seem to be more accepted in the BP variety. The chapter considers headed relatives (HR), discussing briefly different kinds of analyses and standard and non‐standard strategies; then discusses free relatives (FR) and their various constraints; and introduces some special properties of infinitival free relatives (IFR).