This volume has its origins in a theme session entitled: "Lexical and Grammatical Classification: Same or Different?" from the Fifth International Cognitive Linguistics Conference. It includes theme session presentations, additional papers from that conference, and several invited contributions. All the articles explore the relationship between lexical and grammatical categories, both illustrating the close interaction, as well as questioning the strict dichotomy, between them. This volume promotes a holistic view of classification reflecting functional, cognitive, communication, and sign-oriented approaches to language which have been applied to both the grammar and the lexicon. The volume is divided into two parts. Part I, Number and Gender Systems Across Languages, is further subdivided into three sections: (1) Noun Classification; (2) Number Systems; and (3) Gender Systems. Part II, Verb Systems and Parts of Speech Across Languages, is divided into two sections: (1) Tense and Aspect and (2) Parts of Speech. The analyses represent a diverse range of languages and language families: Bantu (Swahili), Guaykuruan (Pilagá), Indo-European (English, Russian, Polish, Bulgarian, Macedonian, Spanish) and Semitic (Hebrew).