Mainly the same or mostly different? : A corpus study of the level of synonymity between the adverbs mainly, mostly, chiefly and principally

Abstract: The purpose of this paper is to examine the adverbs mainly, mostly, chiefly and principally for their level of synonymity. Dictionaries commonly lists synonyms to their main entries without providing information about commonality, contexts or level of formality or even sample sentences. More often than not this is done in a circular fashion, one main entry is listed as synonym to another which in turn is listed as a synonym to the first. This is confusing to persons not knowing what word to use and when to use it. The adverbs mainly, mostly, chiefly and principally are listed as synonyms to each other in several dictionaries in this circular fashion. By using corpus research I have shown that these adverbs are not the absolute synonyms dictionaries indicate, but differ greatly in usage, context and level of formality. I have investigated real samples of how mainly, mostly, chiefly and principally are used in a British newspaper. From the results I have obtained, I have analyzed the usage of the adverbs and suggested new and improved definitions.