I have a 3-month old baby boy who is raised bilingual (Polish and English). The baby is exposed to different accents of English (American, British, and foreign) on everyday basis. We are hiring a babysitter with a strong accent in English but who is a native speaker of Spanish. We are considering having her speak Spanish to a baby. While I am familiar with research on early simultaneous bilingual acquisition and its benefits on cognitive development, I have not found enough research on advantages and disadvantages of early simultaneous trilingualism. Are you familiar with such studies? Thank you.