The article focuses on the contacts between prescriptive and universal grammar in 18th century British linguistics. The author argues that, contrary to the wide-spread belief, there existed two-way relations between them: on the one hand, practical prescriptive grammar used the principles of universal grammar as the foundation for singling out parts of speech and grammar categories and based normative recommendations upon similarities between languages. On the other hand, the authors of universal grammars showed interest to problems of linguistic norm and gave practical recommendations in the vein of prescriptive tradition.