Please, Rewrite my sentences to prose sentences and correct them grammatically.?

During his tenure with our company, He was responsible for many of the office's basic administrative and clerical functions. John effectively managed several assistants to maintain efficient company operations. While under my supervision, his responsibilities included selecting and supervising workers and civil engineers. John was always willing to offer his assistance and had an excellent rapport with the many constituents served by our office including clients, employers, and other professional organizations. In addition, John was motivated and interested in learning . He is highly respected by the people who work under his supervision . His ability to get work done through the service personnel has been outstanding. He is highly respected by the people who work under her supervision, he is organized, thorough in his paperwork, and is always on time. I am amazed at the ease with which John can fulfill a variety of tasks. He has worked for us not only as a supervisor , but also as a tutor to our employees. I would highly recommend him for any position or career that he may now choose to pursue.