This dissertation explores the diversity and unity of coordination constructions in natural language. Following the goal of bridging syntactic typology with formal semantics, it takes the typological variation in NP coordination patterns as a challenge for semantic theory. Hybrid Coordination in Russian and Comitative Coordination in Q'anjob'al (Mayan) are two original empirical case studies of this dissertation. The main theoretical claims concern the semantics of conjunction. I propose two ways of relating sentential conjunction and NP conjunction semantically, and argue that each of them is beneficial for different coordination constructions in different languages. In Q'anjob'al, discussed in Chapter 2, coordinator "yetoq" "with/and" behaves as consistently non-boolean. I argue for treating its function as plurality formation on entities (for NP conjunction) or discourse units (for clausal conjunction), which helps explain constraints on its usage in both cases. Plurality formation, however, is not appropriate as an interpretive mechanism for Hybrid Coordination (HC), where conjoined phrases bear different thematic roles: Ljubov'--eto kogda kto-to i kogo-to ljubit. love is when someone.NOM and someone.ACC loves. "Love is when someone loves somebody". The syntactic and semantic properties of Hybrid Coordination in Russian are discussed in Chapters 3 and 4. Chapter 5 proposes a unified semantic account for syntactically diverse conjunction patterns based on game theoretic semantics. Sentential conjunction, NP conjunction, Hybrid Coordination, quantifier branching, and respectively-constructions can be successfully analyzed via parallel composition of games. The dissertation expands our knowledge of syntactic diversity of coordination by exploring syntactic differences between what seems to be identical constructions in different languages--comitative coordination in Q'anjob'al and Russian, Hybrid Coordination in Russian and other languages. This work also makes a case for semantic diversity. On this front, the main conclusion simply put is that NP conjunction extended to sentences is not the same as sentential conjunction extended to NPs. On the other hand, I also make a case for semantic unity of various conjunction patterns; as argued in Chapter 5, coordination of NPs and sentences have common interpretive properties in what concerns quantifier (in)dependence and anaphora, and can be analyzed as semantically identical. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]