7 Shull, Sarah 2003 Cognitive linguistics, language pedagogy and the English present tense Peter Rehder Slavistische beitr M Otto Sagner Cognitive Linguistics Aims to demonstrate a semantic unity of verbal prefixes in Slavic languages. Connection between spatial and abstract prefixation applying a cognitive linguistic approach. Used elicited speech samples in Prague and St. Pete. Respondents shown movies. Concludes that prefixes and prepositions are systematic. Identifies primary (source, path, goal), secondary (proximity, contact, contain) and tertiary (direct, contour, encircle) semantic features.Some prefixes are better empty perfectivizers because they do not carry as much inferential baggage as others. They will be perceived as empty only if there is significant semantic overlap between the meaning of the verb and the prefix.Disagrees with Janda about nature of space/cognitive space.