(Be sure to review "Babel, ch.8 in Pinker first -- especially pp.246-255.)
Look/listen at these sites.
(Info on Carl Buck and his work)
(Tell me more about Proto-Indo-European (PIE).)
(What does Old English sound like? Listen!) Or the Lord's Prayer from 11th century.
Some interesting word history sites
http://www.etymologic.com/index.cgi Test your word history knowledge!
Ask Oxford (the dictionary people)
Folk etymologies -- bogus tales about word origins--for example!
Obviously every word we know had to be invented by someone at one time or another. New words appear all the time, internet, baud rate, and modem probably were just unused "possible words" in English phonology when some of us were born. Many of the thousands of words we know however have been around for hundreds, maybe thousands of years, passed from generation to generation, changing sound and meaning perhaps as children learned those words somewhat differently from their parents.
At first thought, no two topics may be further apart. On second thought, however, sounds changes in phonemes are brought about by ne generation slightly changing pronunciations and perhaps minor modifications in phonological rules. Languages die when children stop acquiring them. New ones form when children create them, dramatically, for example in forming creoles from pidgins.
assignment is to pick a word with some history -- one that's been around a few
hundred years -- and find out its origins by looking into an etymological
dictionary that summarizes what is known. There are several in the reference
section of the library and the OED (Oxford English Dictionary) is a good source, too. Don't rely on a small desk
Next you will check into Buck's (1949) book to see what if any "cognates" that word has in other Indo-European language. The book is in the reference section. The book is organized by concepts, like a thesaurus. Your word, if listed, would be an instance of a concept, e.g. body parts, kin, emotions.
A cognate is a word that, from its phonological form and theories of sound changes in languages over time, is thought to be descended from a common "ancestor" word. For example in the reading I have copied a page (about p.34) from Buck showing the words for father, mother, and parents in all 30 or so Indo-European languages listed. It is very likely that the word for "mother" in all of these descends from the language spoken in the Middle -East some 7000 or more years ago. The oldest with written records is Sanskrit, brought to India from Iran and known now as a language of religious significance in India. Panini's grammar of Sanskrit is over 2000 years old, the oldest known grammar.
This language, known as Proto-Indo-European (PIE) was the mother language of all contemporary Indo-European dialects from Celtic, English, and French, to Russian, Greek and some Indian dialects including Sanskrit. (The "proto" means the language was reconstructed on the basis of its descendants.) See Pinker's discussion of William Jone's work, p.251-2.
This is a very simple assignment. Pick a word with some history and list its history as reported, say in the OED. Write a few sentences summarizing that history, referring to your listing. Now go to Buck and see if there's an entry for that word under the relevant concept headings.. If not, just say that -- for example a word borrowed into English from an African language or recently created would not probably have any cognates listed. On the other hand a word like "mother", "think", or "happy" is likely to have an entry and you can look for phonetically similar words and assume that they are cognates. Say approximately how many cognates there are and list several of the cognates, identifying their language.
C. D. (1949). A Dictionary of Selected Synonyms in the Principal
Indo-European Languages,. Chicago: University of Chicago Press. Library
Reference section: P765 .B8
Winchester, S. (1998). The professor and the madman. New York: HarperCollins.
 This is the first dictionary that attempted to include nearly all of the words in a language. It documents the written use of each word. The story of the OED is told in Winchester (1998).
 Main Entry: cog·nate (
Etymology: Latin cognatus, from co- + gnatus, natus, past participle of nasci to be born; akin to Latin gignere to beget -- more at KIN
Date: circa 1645
1 : of the same or similar nature : generically alike
2 : related by blood; also : related on the mother's side
3 a : related by descent from the same ancestral language b of a word or morpheme : related by derivation, borrowing, or descent c of a substantive : related to a verb usually by derivation and serving as its object to reinforce the meaning