GH
Gh
Gh is a digraph found in many languages. In English, historically represented, and still does in lough and certain other Hiberno-English words, especially proper nouns. In the dominant dialects of modern English, is almost always either silent or pronounced . It is thought that before disappearing, the sound became partially or completely voiced to or, which would explain the new spelling - Old English used a simple - and the diphthongization of any preceding vowel.The above text is a snippet from Wikipedia: Gh (digraph)
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