My knowledge came from a book from the library that I checked out sometime in the recent past, but I have no idea which book it was. I suppose it was about the decipherment of cuneifom and hieroglyphics in the Middle East and North Africa. ;-) Sometimes I 'graze' the new book shelves in the history and social sciences sections of the library looking for an interesting read.
What makes this subject particularly interesting, and made me remember the tidbit of information that I related to Dave, is that the word 'water' was the key to translating Hittite Cuneiform, because it's the same word phonetically in ancient Hittite and in Modern English. No, really! When I went home I looked this up on the web to verify my memory's claim.
A Czech linguist, Bedrich Hrozny who specialized in Semitic languages decided to attempt the decipherment of the Hittite cuneiform script. He was able to visit Istanbul and obtain copies of some of the cuneiform text from Boghaz Keui. In one text he found a example of two rhyming lines that looked promising. He knew the phonetic values of the cuneiform symbols so he rendered the two lines into the Latin alphabet as:
nu ninda en e-iz-za-te-niHrozny recognized the cuneiform ideogram ninda as representing bread. This led him to speculate that some of the other words in the lines might be for something like eating. He at that point was still considering Hittite as a Semitic language so he was looking for words that might be cognate with words for eating and so forth in other Semitic languages. Hrozny was a Semitic scholar but as a Czech he was also familiar with German. In scanning the lines looking for something that would be associated with bread what does he find at the beginning of the second line but wa-a-tar. It fairly leaps out as virtually the English word water although Hrozny probably saw it as a cognate of the German word for water, wasser. This was the clue to Hrozny that Hittite belonged to the Indo-European language family. He found similarities of the words in the lines to other Indo-European languages and was able to translate the pair of lines as:
Now you will eat bread and drink water. "
In fact, the sound 'ah' as in water, or close to it, is in the word for 'water' in all of the languages that branch out of the Indo-European family, as far as I can find. If you have an example that contradicts this, feel free to post it here.
Latin - aqua
Italian - aqua
Spanish - agua
French - eau
German - wasser
Hindi - pani
Marathi - pan-ni
Arabic - nahla