The influence of spelling on pronunciation is widespread. For example, in often, the 't' used to be silent, but many people now pronounce the word with a [t] in it.
In Brunei, spelling pronunciation is very common, perhaps encouraged by the close link between spelling and pronunciation in Malay. In my data of 53 recordings of the Wolf passage, three speakers produce shepherd with an [f] in the middle, as they assume that the medial 'ph' is pronounced as [f].
Presumably, these speakers do not realise that the word was originally two morphemes, sheep + herd, maybe because there is only one 'e' in the first syllable of shepherd. One assumes that in a word where the two morphemes are more obvious, such as cupholder, speakers would be less likely to pronounce the 'ph' as [f].
1 day ago