Cleft-sentences in Academic Prose: Diachronic Development of their Frequency and Functions in Natural Sciences and Humanities

This diploma thesis maps the diachronic tendencies in the frequency and functions of it-cleft sentences in two sub-registers of academic prose, humanities and natural sciences, from 1800 to 2019. Biber and Gray (2016) showed changes in grammatical complexity in academic writing, namely the shift between phrasal and clausal grammatical complexity and explicitness, which motivated the hypothesis of this thesis, i.e. that the frequency of it-clefts is expected to decrease in the course of 20th century in both sub-registers with the development being faster and more salient in natural sciences. General description presents the syntactic and semantic properties of it-clefts together with discussion about FSP and the distinction between new and given information, as the objective of the thesis is also to study the development of the functional types of clefts. The empirical part analyses a corpus of 170 academic texts, covering the time period under study. It is divided into sections based on time periods displaying similar features concerning the frequency of it-clefts in natural sciences and humanities. The analysis confirms that the expected decrease in the frequency of it-clefts is clearly notable in the case of natural sciences, while in humanities the frequency of it-clefts in individual texts..