One of the central characteristics of human languages is the ability to link simpler units together to form more complex ones. The research area "Syntax and Lexicon" (FB III) is concerned with the syntactic and phonological properties of how clauses can be linked to lexical predicates and to other clauses, with additional consideration of the semantic effects of such linking. The research in FB III has a formal-theoretical foundation, seeking to achieve precise modeling of the results obtained, but always with a view to potential applications. In this vein, we are constructing a database on the selectional possibilities of a large number of clause-embedding predicates in various languages, based on corpus data. This database provides a tool for research in several theoretical and practical areas. It is intended that our investigation of different ways to express a complex state of affairs via clausal combination will feed into a program of research on comprehensibility. This will draw on psycholinguistic eye-tracking and survey methods and lead to the formulation of concrete recommendations, aimed especially at school textbooks.