Words imported from other languages often change pronunciation in the process. They also often change meanings. I think that in French "forte" means strong, while in English it means strength, as in a thing that you're good at. I could be wrong in that instance, but there are plenty of other examples of the phenomenon. These kinds of shifts in meaning and pronunciation are so common that you pretty much have to accept them as correct. Some other examples:
Queen in English comes from kvinne (pron: kvinn-uh) in Norse, which simply means woman.
Husband in English comes from husbond (pron: hoos-bohnd) in Norse, which means farmer (a meaning maintained in "animal husbandry").
And what was the one I saw the other day ... Oh yeah! One of my grad students is French. In an essay in English he used the term savoir faire. He used it, I think, in the French sense, i.e. simply as knack, or know-how, or skill. But moved to English it also carries a bit of a flair, precisely because it is imported. So it has some mystique, some je-ne-sais-quois, some romance, some .... hmmm, is there an Anglo-Saxon word at all that expresses this? Or is the mysterious quality and status of an import word something we can only express with other (meaning-modified) import words?