This paper deals with the contribution of finite verb movement and topicalization to the meaning (sentence mood) of declarative and interrogative clause types in German. Assuming a CP/IP clause structure, I will argue that verb movement to C is triggered by a clause type feature [F1] which relates the descriptive content of the clause to the common information represented in a doxastic conversational background of the discourse context. Relying on the concept of decidedness from Farkas (2003) and the related concept of openness, I will claim that [F1] presupposes that the descriptive content of the clause is undecided/open relative to the relevant conversational background in the given context and that it is supposed to become decided/closed relative to the relevant background in a future context following the context which is projected through the anchoring of the clause in the given context. I will also argue that topicalization is triggered by a feature [F2] which modifies the interpretation of [F1] such that the combination of [F1] and [F2] presupposes that the descriptive content is undecided relative to the relevant conversational background of the given context and that it is supposed to become positively decided relative to that background in the context which is projected through the anchoring of the clause. The proposed theory maintains a balanced position between a maximalist approach to sentence mood presented in Altmann (1987, 1993) and a minimalist approach presented in Portner (2005). It also shows how the use potential of the discussed clause types in German can be derived from the interpretation of the involved linguistic means in a compositional manner.