This article examines the syntax of extra be constructions, common in nonprescriptive English and often considered a curiosity, such as: The problem is, is that she hates apples. It has been claimed that there are many different types of extra be constructions, with the two main types being double be and single be, but this article argues that these distinctions are largely superficial. The article reviews previous accounts, presents the complex data, and categorizes most cases of extra be into one unified syntactic construction, the shared shell-noun construction. It is argued that such constructions are syntactically fairly ordinary biclausal specificational copular sentences, consisting of a setup clause and a resolution clause, which share an argument. A second construction is also proposed for one subset of examples, the linking focus be construction, where be lexicalizes a left-peripheral focus head.