L2 acquisition of tense-aspect morphology: a scientometric study

Research on second-language (L2) acquisition of tense–aspect morphology has grown markedly over the past four decades, yet no panoramic scientometric synthesis exists. Drawing on 2,398 unique publications indexed in Scopus (2,153) and Web of Science Core Collection (269) from 1984–2025, we chart publication trajectories, theoretical emphases, target languages, and thematic shifts. CiteSpace, VOSviewer, and WordStat reveal that annual output surged after 2000 and peaked during 2020–2023, driven primarily by U.S. institutions and prolific authors such as Montrul (53 papers) and Shirai (50). The Aspect Hypothesis remains the most frequently tested framework (18 explicit mentions), while English (2,082 studies) and Spanish (1,415) dominate the language sample, underscoring a continued geographic–linguistic skew. Thirteen cohesive research clusters (silhouette = 0.80–0.997) trace an evolution from form-focused to meaning-oriented and usage-based perspectives. Influential contributions increasingly integrate cognitive, developmental, and instructional lenses. Despite this maturation, under-represented languages and regions persist, signalling the need for cross-linguistic replication and pedagogically oriented, usage-based research.