Using Comparable Corpora to Track Diachronic and Synchronic Changes in Lexical Density and Lexical Richness

This study from the area of language variation and change is based on exploitation of the comparable diachronic and synchronic corpora of 20th century British and American English language (the ‘Brown family’of corpora). We investigate recent changes of lexical density and lexical richness in two consecutive thirty-year time gaps in British English (1931–1961 and 1961–1991) and in 1961–1992 in American English. Furthermore, we compare the diachronic changes between these two language varieties and discuss the results of the synchronic comparison of these two features between British and American parts of the corpora (in 1961 and in 1991/2). Additionally, we explore the possibilities of these comparable corpora by using two different approaches to their exploitation: using the fifteen fine-grained text genres, and using only the four main text categories. Finally, we discuss the impact of the chosen approaches in making hypotheses about the way language changes.