The analysis of 74,000 short stories found that their written work was littered with Americanisms, exclamation marks and references to celebrities.

Researchers who looked at the entries to a national competition found they were increasingly using American words such as garbage, trash can, sidewalk, candy, sneakers, soda, cranky and flashlight.

The stories, written by pupils aged seven to 13, show how fairy cakes are referred to as cupcakes and a dinner jacket has become a tuxedo. ‘Smart’ is now often used for ‘clever’ and ‘cranky’ for ‘irritable’.