Complex sentence: He graduated as a Bachelor of Education from Trinity College, Carmarthen and worked as head-teacher at Ysgol Pentrecelyn, Rhuthun, before he began his training as a professional singer.
Split into simpler sentences: He graduated as a Bachelor of Education from Trinity College, Carmarthen and worked as head-teacher at Ysgol Pentrecelyn, Rhuthun. All this before he began his training as a professional singer.