Many words ("e.g." the words "beef" and "pocket") entered the English language from the Norman language following the Conquest of 1066. They have been so thoroughly integrated into the language that they are not generally considered to be foreign, and they follow the usual laws of English phonetics perfectly. Their current pronunciations have generally changed from the original ones, but no-one considers them to be mispronunciations, because the words were adopted so long ago.