Complex sentence: Following the departure of Jenna Coleman as Clara Oswald at the end of the ninth series, the tenth series will introduce a new companion for the Doctor, who, as of 19 March 2016, the new companion has been cast.
Split into simpler sentences: Following the departure of Jenna Coleman as Clara Oswald at the end of the ninth series, the tenth series will introduce a new companion for the Doctor. As of 19 March 2016, the new companion has been cast.