My students of ESL from Guatemala all notice that bilinguals with Spanish and a Mayan language or only a "dialecto" learn English very fast. Any explanations?
I checked a Quiche grammar and there are glottal stops in Quiche, the sh sound exists (not in Spanish) and the o umlaut of the English -er or -ir of "Thursday" My Spanish learners often say "Day after Wednesday" to make that word plain. On the other hand, does a bilingual person find a third language easier because of sociological forces of being less uptight? Brain neurons ready to form new connections? Or, is this just an urban legend?