Abstract
The paper focuses on relative clauses introduced by jak 'how' in spoken Czech, relying on corpus data. It argues that these clauses, in contrast to relative clauses introduced by co 'what', are functionally specialized, in that they are based on propositions that form a part of the shared knowledge of the speaker and their interlocutor(s), i.e., they have what could be described as a recognitional function.
This is supported mainly with arguments based on the distribution of determiners of the head noun, the use of verbal mood and tense in co- and jak-clauses, and the use of recognitional demonstratives in co- and jak-clauses. Previous claims about the use of resumptive pronouns in co- and jak-clauses, based on written language, are revised, and it is illustrated that most of the previous generalizations do not square well with the data from spoken Czech.