From the archives...
The following question, from 2015, was originally posted on the LOE Forum.
So, WH says /w/ or /wh/, and I know Essentials offers the explanation that in some dialects there is a noticeable difference in pronunciation between W and WH, but in some words like WHOLE, WH says /h/ not /w/.
(Side note, in my 1957 unabridged webster dictionary, its pronunciation guide shows the pronunciation of WH has /hw/ which makes a lot of sense in words like Whale, we do kind of breathe out when we say it so it has that /h/ gust of air before we get to the /w/ sound.) But, still don't understand WHOLE. There is no /w/ sound in that word.
You are correct: whole, who, and whose are unusual and don't follow the usual sound of WH.
The interesting thing about them, though, is that we usually still form our mouths as if we were saying the unvoiced /wh/ (or /hw/) when we pronounce them, even though the /w/ sound has dropped out. You can read more about this on our blog: The Spelling of "Who."
By the way, Wikipedia has an interesting article with more information, from an etymological and linguistic standpoint, about why the pronunciation shift has occurred.