here's your corrected version:-
During the past three years, I have been studying Information Technology at Groep-t "The English group". I graduated this year with very good grades and also I have very good grades in my first and second year. That's the reason why I am being encouraged and optimistic about enrolling in the engineering program.
Furthermore, I have been working both full-time and part-time in Marketing, Hardware support for the last 3 years and currently I’m working part- time for “****” As “****”.