Cho, Youngsoon. 2002. Jespersen and Sonnenschein. The History of English, 14. The purpose of this paper is to examine the argument between Jespersen and Sonnenschein on English grammatical categories of case, mood and tense. Jespersen took the form-based position: categories should be recognized only if formal expressions are found in that language. On the other hand, Sonnenschein emphasized that function or meaning should also be considered. Consequently, the number of English cases, the mood of a verb-form, and the number of English tenses differ in their English grammar descriptions. The argument raises further questions to consider: the relations of form, function and notion, and the application of the facts found in historical linguistics and comparative linguistics in the description of a language.