This article presents a comprehensive corpus-based study of language change in English from the Old English period through Modern English. Using historical corpora (e.g. the Helsinki Corpus, Penn Parsed Corpora, and the Corpus of Historical American English), we trace diachronic patterns in morphology, syntax, and vocabulary. We outline the gradual loss of inflectional morphology (e.g. case and gender) after the Norman Conquest, and the rise of fixed SVO word order in Early Modern English (EModE) . Vocabulary analysis reveals waves of borrowing (e.g. French and Latin in Middle English) and ongoing lexical innovation. The study employs frequency analysis and syntactic querying on corpora to quantify changes (e.g. tracking the increase of do‐support and passive constructions). We summarize key findings in a comparative table of linguistic changes over time. The results support classical historical linguistics claims with quantitative evidence. We conclude that large diachronic corpora enable precise measurement of long-term trends while noting the need to account for genre and text-type shifts. This research bridges theoretical accounts of English grammar change with empirical corpus data, highlighting trends documented in recent studies and offering a model for corpus-driven historical linguistics. Keywords: Corpus linguistics, English language history, lexical change, morphological change, syntactic change