sentences:  There is controversy about whether parrots are capable of using language, or merely mimic what they hear.However, some scientific studies—for example those conducted over a 30-year period by Irene Pepperberg with a grey named Alex and other parrots, covered in stories on network television on numerous occasions—have suggested that these parrots are capable of using words meaningfully in linguistic tasks.Some in the scientific community are skeptical of Pepperberg's findings, pointing to Alex's communications as operant conditioning.