In the Prague Dependency Treebank, a part of the texts from the Czech National Corpus is being annotated on several layers, including the underlying (tectogrammatical) representations. The usefulness of such a treebank is briefly characterized and a large set of topics is discussed for which further monographical research appears to be necessary. The future discussion and elaboration of these topics can be carried out much more effectively with the use of the annotated corpus, and the results thus gained may then serve to an enrichment of the descriptive framework and of the annotation procedure.