In the present study, I investigate the grammar and usage of English exclamative clauses of the type What a wonderful journey this is! and How wonderful this journey is!. Building on existing research, I argue that the exclamative clause type can be motivated both syntactically and semantically/pragmatically. In the main part of my study, I offer a usage-based analysis of English exclamative clauses drawing on data from the British National Corpus and the International Corpus of English, British Component. I consider 703 tokens of what-exclamatives and 645 tokens of how-exclamatives. My analysis reveals that English exclamatives typically occur in reduced form lacking an overt verbal predicate, i.e. What a wonderful journey! or How wonderful!. I provide an explanation for the predominance of reduced forms based on the semantico-pragmatic properties of exclamations. Moreover, I argue that the usage properties of exclamatives render it a marginal clause type, as it is highly infrequent and predominantly appears in non-clausal forms. Usage data point to a cline of clause types as the more appropriate approximation of reality instead of the familiar distinction between major and minor clause types.