In my master thesis I present the results of a study of adverbial modifiers rather, quite, pretty and fairly. The aim of the present thesis is to investigate how synonymous rather, quite, pretty and fairly are. The main argument is that the selected English adverbs are synonymous only to some extent as they share the meaning of in some degree . Thus, they can be considered partial synonyms.The important research areas are the study of the meanings of the set of adverbial modifiers based on the information from the Merriam Webster s Online Dictionary and the study of the evidence found in the British National Corpus. The BNC material was processed with the help of the old-fashioned manual work and modern computerized technology. The evidence was processed with the help of the concordance tools (the BNC concordancer and the WordSmith concordancer) that allow us to statistically analyse and arrange the collocations of a word.The most interesting results come from the study of the collocational patterns of rather, quite, pretty and fairly. Working on the language material I focused on the semantic prosody of the adverbial modifiers. An interesting supplement to the master thesis is a test with native speakers. Its aim is to investigate the preferences of the modern users of the English language when they deal with the adverbial modifiers.