Oblique subjects involve a number of issues in their research, as they represent an uncharacteristic intersection of syntactic and semantic features. This is most evident when they are encoded by the dative case, exhibiting the syntactic features of indirect objects and the semantic and pragmatic features of subjects. However, they are often dismissed by both traditional grammar and modern linguistic research due to their failure to fulfil the syntactic criteria deemed necessary for subjecthood, where traditional grammar focuses on case marking and predicate agreement, while modern linguistic theory focuses on behavioural properties typical of subjects. However, the methodologies of both approaches are somewhat inadequate, as they can result in language-specific definitions of subjects in some cases, while in others they cannot sufficiently explain the combination of subject and indirect object features of dative subjects. Part of the problem lies in their approaches being based on the prototype theory of categorisation, which views subjects as a set of different features, but does not state which are required for subjecthood. However, a different approach based on the classical theory, which defines categories in terms of sufficient and necessary features, has provided a subject definition that circumvents those issues. It defines subjects in terms of only one syntactic feature, the position of arguments in a predicate’s subcategorization frame. This approach has acknowledged dative subjects as members of the subject category in multiple languages, even in those where dative subjects have been rejected as a concept by both traditional grammar and modern linguistic research. This thesis will explore the issues posed by dative subjects primarily in English and Croatian, as these two languages possess experiencer subjects, but not dative subjects, although for different reasons. Additionally, the methodological issues present in traditional grammar and linguistic theories will also be presented through the research done on experiencer and dative subjects in these two languages. Finally, the merits of an alternative definition based on classical theory will be examined, as they include historical comparative research and a greater inclusion of native speakers’ opinions. Its viability as a new universal subject definition will be tested, focusing specifically on its application to oblique subjects.