Complex sentence: He attended Robert Gordon's College in Aberdeen, where he received a technical education, before being apprenticed in 1888 to the Great North of Scotland Railway (GNoSR) at their locomotive works at Kittybrewster, just outside Aberdeen.
Split into simpler sentences: He attended Robert Gordon's College in Aberdeen, where he received a technical education. He was apprenticed in 1888 to the Great North of Scotland Railway (GNoSR) at their locomotive works at Kittybrewster, just outside Aberdeen.