Linguistic evolution is much like biological evolution in that there is no a priori direction for it to go. There is a sort of natural selection in that words

Linguistic evolution is much like biological evolution in that there is no a priori direction for it to go. There is a sort of natural selection in that words that don't get used don't generally get passed on to the next generation. Text and other media allow some of these words to be recovered in later generations. If history is any indication, in 100 years American English will have some precise ways of expressing things, some loose ways of expressing things, and various groups of people will be unreasonably upset with one situation or the other. If you're interested in the mechanisms of language change, I found the (2000) 3rd edition of Jean Aitchison's _Language Change: Progress or Decay?_ both readable and worth reading. There is a 4th edition, published in 2013: http://www.cambridge.org/us/academic/subjects/languages-linguistics/historical-linguistics/language-change-progress-or-decay-4th-edition http://www.cambridge.org/us/academic/subjects/languages-ling...