There is a tendency for the existential, copulative, and verb-category carrying dummy elements of a language (a) synchronically to interpenetrate in complex patterns of suppletion, semantic overlapping, and partial homonymy, and (b) diachronically to merge, split, and otherwise restructure among themselves.
Standardized
There is a tendency for the existential, copulative, and verb-category carrying dummy elements of a language (a) synchronically to interpenetrate in complex patterns of suppletion, semantic overlapping, and partial homonymy, and (b) diachronically to merge, split, and otherwise restructure among themselves.