This paper describes and analyzes a series of paradigmatic oppositions between N’ constructions in the P-Celtic languages (Welsh, Breton, Cornish) which serve to code expressive pragmatics of adjectives. The paper considers both paradigmatic and syntagmatic aspects of these constructions, and shows that asymmetric interaction of constructions in paradigms influences their purely formal syntagmatic interactions. A typology of expressive categories is built to serve as a framework for comparison between constructions. It is argued that a view of grammar that includes both formal and functional dimensions (‘the coding view’) also provides valuable insight in matters of purely formal constructional interaction.