Complex sentence: A lifelong fan of "Doctor Who", Moffat has written several episodes of the revived version and succeeded Russell T Davies as lead writer and executive producer when production of its fifth series began in 2009.
Split into simpler sentences: A lifelong fan of "Doctor Who", Moffat has written several episodes of the revived version and succeeded Russell T Davies. He became lead writer and executive producer when production of its fifth series began in 2009.