What is it that makes one American accent different from another American accent? Primarily, it has to do with the way that vowels are pronounced. When American linguists are poking around for clues to a person's dialect, they ask them to pronounce words that have different vowel sounds in different parts of America. Whether the words 'cot' and 'caught' are pronounced the same or not can be an excellent clue. If they are pronounced the same, the speaker might be from New England, Texas or the Midwest. If they're pronounced differently, the speaker might be from New York, Philadelphia or the South. There are distinctive regional patterns in the pronunciation of vowels that can be dead giveaways. The 'Northern Cities Vowel Shift' is changing the speech of about 30 million people in a very specific part of the country.

Another indicator of dialect is the use of the 'r' sound at the end of words. This is not quite as reliable, because it is now considered to be proper speech to use an 'r' sound, so the use of the 'r' sound is sometimes best as an indicator of how uptight a person's primary school English teacher was. However, if