The article presents a critical analysis of approaches to defining sentential subjects as non-canonical syntactic units consisting of a finite or a non-finite clause. The major issue discussed is the position of the sentential subject in the tree structure debating whether it lands in subject position as a result of movement or it is base-generated in the subject position. Additionally, a claim is made that sentential subjects are not true subjects, but rather topics, suggesting that a different constituent occupies the canonical subject position. Therefore, sentential subjects appear to behave akin to both topics and regular subjects. They cannot generally occur in subject positions in embedded clauses, subject-auxiliary inversions and after topicalised units, yet they trigger subject-verb agreement. When considering these two alternatives, the author finds it important to distinguish between the pragmatic function and the syntactic position. Though subjects have been studied in various linguistic schools, a common consistent opinion on the sentential subject status has not been reached. The discrepancies in existing views are revealed in similar examples analyzed as grammatical or ungrammatical within different scientific frameworks. Distributional and transformational tests, along with the study of the information structure of the utterance aimed at proving the acceptability / unacceptability of sentential subjects show mixed results and sometimes contradictory analyses. The research suggests that ungrammatical sentential units are normally neutralised by alternative structures that function as syntactic blockers. To address the complexity in exploring sentential subject,the author advocates for a multifactor approach, which takes into account structural, distributional, weight ratio, semantic, pragmatic and psycholinguistic characteristics of subjects in a variety of configurations to ensure understanding the degree of subjecthood of syntactic structures and their systemic arrangement from the core to the periphery. In conclusion, the article emphasizes the need for a comprehensive approach to studying sentential subjects, acknowledging their multifaceted nature and aiming for a systemic understanding of subjecthood within linguistic frameworks.