Now that I am rambling about etymology, another cool thing: We spell and say the plural of "wife" as "wives". This is because of how the voiced "e" changed the pronunciation of the unvoiced "f" to a voiced "v". ("v" and "f" are the same sound with the only difference being if you are engaging your vocal folds or not. Same with "z" and "s", "b" and "p", and some others).

The same happened with "knife" and "knives", and the pronunciation of "path" vs "paths" (the "s" sound is voiced, and caused the "th" to be voiced as well).