The article deals with postmodifi cation by fi nite and non-fi nite relative clauses in four different text types (newspaper, academic prose, fi ction, and interview) of spoken and written English. It presents detailed descriptions of the distribution of particular structures and comparisons with their distribution in other text types. The types of postmodifi cation (restrictive vs. non-restrictive) used in different text types were examined in order to fi nd out to what extent they are employed in the different texts and which forms of postmodifi cation (fi nite vs. non-fi nite) are used in which text type. Besides other fi ndings, the results of the analyses show that the occurrence of fi nite and non-fi nite clauses as well as their basic function depends on the degree of formality of the text types.