English language English was the language originally spoken in England . It was also spoken over much of Earth . Though there were many speakers of English , it was not always the most common language . In the early 21st century , Mandarin was most widely spoken . ( TV : " " ) It was said to be easier for the Eurozone to know English than to teach the world other languages . ( PROSE : " Trading Futures " ) The Doctor ' s favourite language was English . ( AUDIO : " . . . ish " ) The First Doctor told Dodo Chaplet that he would teach her proper English after she said " okay . " ( TV : " The Ark " ) Edward Waterfield , being from 1866 , had to be explained that " okay " meant something was " good " or that it would be taken care of . ( TV : " The Evil of the Daleks " ) The Celestial Toymaker asked Charlotte Pollard about possible code words to a puzzle he ' d set for her : " Do you know how many four - letter words there are in the English language ? How many in all languages ? Approximately 400 , 000 . " ( AUDIO : " Solitaire " ) The language was used both in Great Britain and in the United States of America , but each culture had their own variations of certain words or phrases . The letter ' Z ' was pronounced " zee " in America and " zed " in Britain , ( TV : " Vengeance on Varos " ) while words like " grey / gray " and " checkerboard / chequerboard " had different spellings . ( AUDIO : " The Reaping " , PROSE : " Deceit " ) Additionally , the English and Americans had different words for the same thing , such as the " bumper " or " fender " of a car . ( AUDIO : " " ) American English was also a wholly different dialect to Oxford English or Cockney English . ( PROSE : " Who Killed Kennedy " , TV : " The Unicorn and the Wasp " ) Accent s also differed between those mentioned and Scottish ( TV : " The Eleventh Hour " , " Deep Breath " ) or Northern English , ( TV : " Rose " ) or , outside of the UK , between New Zealand ( " Kiwi " ) English , and that which spoken by South Africans . ( PROSE : " The Comet ' s Tail " ) Shanquis was terraformed by English - speaking human s . The terraforming device was left online after the humans on the planet died out , allowing anyone who spoke English to control the structure of Shanquis . ( AUDIO : " Bernice Summerfield and the Criminal Code " ) After World War II , Winston Churchill began writing a history of the English - speaking peoples . The earliest volume was about the period of Julius Caesar ' s invasion of Britain in the 1st century BC . ( AUDIO : " Living History " ) When Doña Arana heard the Androgum Shockeye speak in Seville in 1985 , she recognised his words as English . ( TV : " The Two Doctors " ) Tegan Jovanka ' s father William Jovanka used to say that " if " was the most powerful word in the English language . ( TV : " Castrovalva " ; AUDIO : " Psychodrome " ) When he began learning English , Matteusz Andrzejewski would read books in the language , including a book about a place called Narnia , at his mother ' s suggestion . ( TV : " Detained " ) Leela could not read English . ( AUDIO : " Beautiful Things " ) By the 50th century , phonetic spelling was common in English . For instance , " Emergency Exit " was spelled " Emergensee Eggsit " and " Service Elevator " was spelled " Servis Ellyvater " . ( AUDIO : " Revenge of the Swarm " )