The article deals with two of the long-standing problems in English linguistics: whether it is possible that each noun can have both count and mass senses, and the problem of determining a complete list of the regularities of count-to-mass and mass-to-count changes. While there have been numerous attempts to solve each of these problems, this article shows the results of applying Cognitive Grammar to them.

The analysis covers a set of concrete nouns representative of English – sixty nouns with different ontological properties and all frequencies of occurrence. These are nouns that are classified by dictionaries as solely count and solely mass. Because of its usage-based character, the analysis scrutinises over 1,700 real-life utterances produced by native speakers of English. The analysis shows that even such nouns possess senses whose properties are the reverse of the properties of the nouns’ basic senses. A thorough examination of the nouns’ basic and extended senses leads to certain grammatical regularities of count-to-mass and mass-to-count changes. The analysis not only systematises the grammatical regularities determined so far and solves many problems that can be noticed about them, but also proposes novel regularities.