The complex characteristics of lexical blending have long troubled mainstream word formation research to the extent that it has typically been considered a peripheral issue in linguistics. In recent years this has begun to change, and there is currently a growing body of evidence uncovering the intriguing nature of this word formation process. In the present study, underlying principles and usage-based aspects of lexical blends were examined. Analyses of derivatives of three matrix words, republican, liberal, and vegetarian, revealed the impact of three cognitive constraints on the use of lexical blends: schema transfer effects, neighborhood effects, and effects of the influence from morphological lexicalization. The first constraint fueled blend formation, while the other two displayed a hampering effect on the use of lexical blending. Furthermore, a study of the word class distribution in the datasets showed that there were significant differences in the grammar of lexical blending and compounding, respectively. Keywords: lexical blending, cognitive constraints, word formation processes, language in use, investigation, corpus