“For all intensive purposes.” A scientist just wrote this to me. (By the way, can you tell that I’m trying to single-space after my periods? It hurts.)
It’s sort of like the effect of a great collective game of “Telephone.” (You know, where you sit around a table and whisper something to the person next to you, and they whisper it to the person next to them, and when it gets all the way around the table, it is often transformed beyond recognition.) That, in turn, is the effect of becoming an ever less literate and more oral and visual culture, so that the ear is not corrected by the eye.
The opposite problem, in a perhaps too-literate culture, would be an amusing subject for another post. (I’m doing some “real” writing right now and am impatient to get back to it.) That is the often lifelong mispronunciation of words that one has oft read but never heard. Stay tuned, or at least, tune in again.