This study investigates the evolution and prevalence of variant forms in English writing instruction within an international context, utilizing a time series analysis of corpus data. Recognizing the dynamic nature of language, especially in educational settings, this research aims to identify and analyze the changes in teaching methodologies and language usage over time. By examining a comprehensive corpus compiled from diverse international sources, the study focuses on how English writing instruction has adapted to linguistic variations and evolving pedagogical approaches.The methodology involves a quantitative analysis of corpus data spanning several decades, enabling a longitudinal view of trends in English writing teaching. The corpus includes a wide range of educational materials, academic publications, and teaching resources from different countries, ensuring a global perspective. Time series analysis is employed to track the frequency and context of various teaching practices and linguistic forms, offering insights into their development and dissemination.Key findings reveal a significant shift in teaching strategies, reflecting an increased emphasis on learner-centered approaches and the integration of digital technologies. Variants in language usage, influenced by cultural and regional differences, are also evident, highlighting the importance of context-specific teaching methods.