Complex sentence: She taught English part time at Barnard for several years, she declined a full-time position and took a leave of absence to undertake her Ph.D. in English and comparative literature at Columbia in three years.
Split into simpler sentences: She taught English part time at Barnard for several years. She declined a full-time position and took a leave of absence to undertake her Ph.D. in English and comparative literature at Columbia for three years.