Companion (Doctor Who) companions too have been depicted in the revived era, such as Jo Grant (n/k/a Jo Jones)'s grandson Santiago Jones; and Sarah Jane Smith's parents, adopted son Luke Smith, adopted daughter Sky Smith, and alternate timeline fiancé Peter Dalton; and Alistair Lethbridge-Stewart's daughter Kate Stewart. Another change in the revived era is the depiction of many companions' pre-Doctor lives, particularly their childhoods; no companion was so depicted in the classic era, aside from John Benton being temporarily 'de-aged' by The Master. Companions Rose Tyler, Mickey Smith, Adelaide Brooke, Amy Pond, Rory Williams, River Song and Clara Oswald have all been portrayed
David Crystal difficult to spell. His companion book, "Making a Point: The Pernickety Story of English Punctuation" came out in 2015 from Profile Books (UK) and St. Martin's Press (USA). Crystal is a proponent of a new field of study, Internet linguistics, and has published "Language and the Internet" (2001) on the subject. Crystal's book "" (2008) focused on text language and its impact on society. From 2001 to 2006, Crystal served as the Chairman of Crystal Reference Systems Limited, a provider of reference content and Internet search and advertising technology. The company's iSense and Sitescreen products are based upon the patented