The Structure of Sentences

Linguistics up until the middle of the 20th century had produced a wealth of descriptions for previously unexplored languages and had developed a good understanding of phonological and morphosyntactic phenomena, especially with respect to language change. However, there was no enterprise that worried about syntactic structure per se. That is, although there was work on the relative placement of individual elements (e.g., clitics, subject-object-verb order, pre- vs. postpositions), there was no investigation into deeper questions of syntax, such as the complex syntactic interplay between negation, question words and auxiliaries, or the identification of syntactic effects due to elements not visible at the surface (in parallel to phonological effects of underlying, but invisible phonemes). With the realization that much work needed to be done in this area, the linguistic game in the 20th century changed.

The change in linguistic awareness did not come about unreflectedly, as the following quote from Zellig Harris' book Structural Linguistics shows.