The most commonly accepted line of inquiry to explain this is Noam Chomsky's minimalist approach to syntactic representations. In 2016, Chomsky and Berwick defined the minimalist program under the Strong Minimalist Thesis in their book "Why Only Us" by saying that language is mandated by efficient computations and, thus, keeps to the simplest recursive operations. The main basic operation in the minimalist program is merge. Under merge there are two ways in which larger expressions can be constructed: externally and internally. Lexical items that are merged externally build argument representations with disjoint constituents. The internal merge creates constituent structures where one is a part of another. This induces displacement, the capacity to pronounce phrases in one position, but interpret them elsewhere.