This book is a groundbreaking, paradigm-shifting look at the "languages/tongues" problem (γλῶσσαι/glṓssai) of the first-century AD Corinthian church. It adduces that in a multilingual setting, new converts were expressing themselves in their native dialect without translation, where Koine Greek was not yet overriding all regional dialects. This cuts against the idea that the inferred earthly languages were miraculously and instantaneously given--an idea not found before 160 AD. Vellacott's comprehensive linguistic, cultural, historical, contextual, exegetical and translational research also weighs against the view that "tongues" were "heavenly languages," as claimed by Pentecostals/Charismatics. Primary sources indicate that this novel trend was started about 145 years ago by German, higher-critical scholars and seized upon after the 1906-15 Los Angeles Azusa Street Revival's supposed supernaturally endowed earthly languages proved to be a mirage, whereupon a redefinition to "heavenly/angelic, non-earthly languages" occurred. This book soundly establishes the credibility of an ancient third view regarding "tongues"--that they were non-supernatural, learned, earthly languages. This is arguably the earliest view of New Testament tongues/languages.