ABSTRACT
The present article offers a study of the negative prefixes in English and Bulgarian classifying them according to certain criteria and trying to point out some specific problems in translation of words with such prefixes from English into Bulgarian, as well as suggest some techniques of getting over these difficulties. More attention is paid to the English language since the direction of this study is from English to Bulgarian. Here, the English negative prefixes are classified in terms of their meaning, origin, productivity and valency, whereas only a general systematized overview is provided for the Bulgarian negative prefixes.