This study comprehensively investigates the historical development and contemporary usage of English curse words, integrating diachronic corpus linguistics with sociolinguistic survey data. Utilising a custom-built 1.5 million-token corpus spanning texts from the Middle English period to 2023, the research traces frequency trends, tone variations, and semantic shifts of twenty core profanities. Simultaneously, a quantitative survey of 500 global respondents explores the acceptability, frequency, and context of swearing across demographic groups, revealing strong generational and educational influences. Findings indicate a marked increase in profanity usage and growing normalisation in digital and informal settings. Words such as fuck, bitch, and shit have expanded semantically, now functioning across euphemistic, ironic, and neutral registers. Contrary to earlier studies, gender differences in swearing behaviour are minimal, while education and digital exposure significantly affect usage patterns. This research contributes to evolving theories of politeness, speech act pragmatics, and language change, framing profanity as a fluid linguistic tool reflective of broader cultural and communicative shifts in modern English.