Complex sentence: In 2012 and 2013, BBC Radio 4 aired series of his comedy "I, Regress" where he takes the role of Dr Berry, a brilliant but unorthodox regressive therapist.
Split into simpler sentences: In 2012 and 2013, BBC Radio 4 aired his comedy series "I, Regress". In it he takes o the role of Dr Berry, a brilliant but unorthodox regressive therapist.