Sentence structure and discourse structure
The present contribution represents the first step in comparing the nature of syntactico-semantic relations present in the sentence structure to their equivalents in the discourse structure. The study is carried out on the basis of Czech manually annotated material collected in the Prague Dependency Treebank (PDT). According to the analysis of the underlying syntactic structure of a sentence (tectogrammatics) in the PDT, we distinguish various types of relations that can be expressed both within a single sentence (i.e. in a tree) and in a larger text, beyond the sentence boundary (between trees). We suggest that, on the one hand, semantic nature of each type of these relations corresponds both within a sentence and in a larger text (i.e. a causal relation remains a causal relation) but, on the other hand, according to the semantic properties of the relations, their distribution in a sentence or between sentences is very diverse. In this study, this observation is analyzed in detail for three cases (relations of <i>condition</i>, <i>specification</i> and <i>opposition</i>) and further supported by similar behaviour of the English data from the Penn Discourse Treebank.