Complex sentence: Bernadette Maryann Rostenkowski, Ph.D. is a fictional character on the CBS television series "The Big Bang Theory", portrayed by actress Melissa Rauch, Bernadette is initially a recurring character for the third season, but promoted to series regular from the fourth season onwards.
Split into simpler sentences: Bernadette Maryann Rostenkowski, Ph.D. is a fictional character on the CBS television series "The Big Bang Theory". Portrayed by actress Melissa Rauch, Bernadette is initially a recurring character for the third season, but promoted to series regular from the fourth season onwards.