https://en.wikipedia.org/wiki/Phonological_history_of_English_consonants
H-cluster reductions. Reduction of /hw/ – to /h/ in a few words (such as who), but usually to /w/, for the great majority of English speakers (so that whine comes to be pronounced the same as wine). Reduction of /hl/, /hr/ and /hn/, with the loss of the initial /h/ in Middle English. Reduction of /hj/ to /j/ in a few American and Irish dialects (so that hew is pronounced like yew).