Complex sentence: He worked as a clerk until 1934, then studied speech and drama at the Regent Street Polytechnic and the London Speech Institute under Margaret Gullan, before studying phonetics under Daniel Jones at University College London and joining the London Verse Speaking Choir.
Split into simpler sentences: He worked as a clerk until 1934, and then studied speech and drama at the Regent Street Polytechnic and the London Speech Institute under Margaret Gullan. He went on to study phonetics under Daniel Jones at University College London, and joined the London Verse Speaking Choir.