Peter Giles

“ Throughout the history of English the sound seems to have remained the same—the consonantal u. For this value as well as for u Latin always used only V; in Greek, except in a few dialects, the consonant value was early lost (see under F) . W is produced by leaving a very small opening between the slightly protruded lips while the back of the tongue is raised towards the soft palate and the nasal passage closed. The ordinary w is voiced, but according to some authorities the w in the combination wh (really hw) is not, in when, what, &c., even when the h is no longer audible. ”

“ The combination WH (hw) represents the Indo-European qṷ when changed according to Grimm's law from a stop to a spirant. Thus what corresponds philologically to the Latin quod and the first syllable of the Greek ποδ-απός. ”