This thesis is concerned with two semantically different types of definite articles in German. While the existence of distinct article paradigms in various Germanic dialects and other languages has been acknowledged in the descriptive literature for quite some time, its theoretical implications have not been explored extensively. I argue that each of the articles corresponds to one of the two predominant theoretical approaches to analyzing definite descriptions: the 'weak' article encodes uniqueness. The 'strong' article is anaphoric in nature. In the course of spelling out detailed analyses for the two articles, more general issues relevant to current semantic theory are addressed, in particular with respect to the analysis of donkey sentences and domain restriction.

Chapter 2 describes the contrast between the weak and the strong article in light of the descriptive literature and characterizes their uses in terms of Hawkins (1978) classification. Special attention is paid to two types of bridging uses, which shed further light on the contrast and play an important in the analysis developed in the following chapters.

Chapter 3 introduces a situation semantics and argues for a specific version thereof. I propose that situation arguments in noun phrases are represented syntactically as situation pronouns at the level of the DP (rather than within the NP). I then argue that domain restriction (crucial for uniqueness analyses) can best be captured in a situation semantics, as this is both more economical and empirically more adequate than an analysis in terms of contextually supplied `C'-variables.

Chapter 4 provides a uniqueness analysis of weak-article definites. The interpretation of a weak-article definite crucially depends on the interpretation of its situation pronoun, which can stand for the topic situation or a contextually supplied situation, or be quantificationally bound. I make a proposal for how topic situations can be derived from questions and relate this to a more general perspective on discourse structure based on Questions Under Discussion (QUD) (Roberts 1996, Büring 2003). I also show that it requires a presuppositional view of definites. A detailed, situation-semantic analysis of covarying interpretations of weak-article definites in donkey sentences is spelled out as well, which provides some new insights with regards to transparent interpretations of the restrictors of donkey sentences.

Chapter 5 deals with so-called larger situation uses (Hawkins 1978), which call for a special way of determining the situation in which the definite is interpreted. I argue that a situation semantic version of an independently motivated type-shifter for relational nouns (shifting relations to properties) brings about the desired effect. This type-shifter also applies to cases of part-whole bridging and provides a deeper understanding thereof. Another mechanism, namely that of Matching functions, gives rise to similar effects, but depends heavily on contextual support and cannot account for the general availability of larger situation uses.

The anaphoric nature of the strong article is described and analyzed in detail in chapter 6. In addition to discourse anaphoric uses, I discuss covarying interpretations and relational anaphora (bridging with the strong article). Cases where uniqueness does not hold (e.g., in bishop sentences) provide crucial evidence for the need to encode the anaphoric link between strong-article definites and their antecedents formally. The resulting dynamic analysis of strong-article definites does this via a separate anaphoric index in the DP.