This thesis presents a historical review of literature on small clauses, typically defined as tenseless [NP XP] structures, where XP is non-verbal. Additionally, this thesis argues for a universal structure for small clauses. The structure is binary-branching and contains a functional predicational projection, referred to here as PrP. The range of possible syntactic properties of the Pr head explains the differences in small clauses crosslinguistically. The structure argued in this thesis is based primarily on data from English, Russian, Irish, Chinese, and Polish. The syntactic possibilities of the T head and Pr head in combination can explain the range of copular clauses cross-linguistically.