@Joe Nation,
I only dislike the thought of language changing if there is danger of it become too homogenized. Although it thought it was somewhat silly, i did understand the anti-"Franglais" movement of the late 1960s.
The commerce in languages can be interesting, though. There was an event in Europe in the late 16th and early 17th centuries known as the vowel shift. The pronounced value of vowels changed. This is why the French word for French (masc.) is
français--but the name is François. At one time, the French word for French (masc.)
was françois.
Well, before the Great Vowel Movement (as i like to think of it), there was a Greek-root word in French--
franatique. From that, we got frantic. Then, after Europe had finally passed the Great Vowel Movement, that word in French became
frénétique. It was borrowed once again, by middle class travelers who wanted to show their sophistication. I've had people try to tell me that there is a difference in the words frantic and frenetic--but i ain't buying it.
This can work between other languages, of course. German tourists staying in French hotels in the 19th century would see a transom over the door, something which apparently had not yet appeared in Germany. They would point to it, and then ask the chambermaid "Was ist das?" Well, the chambermaids were country girls, and neither had any German nor had ever seen a transom themselves, and they took the question for a statement. To this day, the commonly used french word for a transom is
vasisdas, although there is an "official" word--which i don't remember.