 On the basis of his linguistic analysis, Samarin defined Pentecostal glossolalia as "meaningless but phonologically structured human utterance, believed by the speaker to be a real language but bearing no systematic resemblance to any natural language, living or dead".Practitioners of glossolalia may disagree with linguistic researchers and claim that they are speaking human languages (xenoglossia).Felicitas Goodman studied a number of Pentecostal communities in the United States, the Caribbean, and Mexico; these included English-, Spanish- and Mayan-speaking groups.