The phonological history of English consonant clusters's part of the phonological history of the English language in terms of changes in the phonology of consonant clusters. H-cluster reductions The h-cluster reductions are various consonant reductions that've occurred in the history of English involving consonant clusters beginning with /h/ that've lost the /h/ in certain varieties of English. Wh-cluster reductions The hole-whole merger's the replacement of /ʍ/ with /h/ before the vowel… (More on Yod-coalescence)