Why do Americans pronounce herbs without the h?
The word reached English from Latin “herba” via the French “herbe,” a language that had dropped the aspirate in all Latin etonyms around the third century (as had the ancestors of Spanish, Portuguese, Romanian and most dialects of Italian). It was, like “honour”, pronounced in English with a silent initial H until around 1825 when in southern England, members of the socially aspirant middle classes, anxious not to be taken for lower class Londoners (who dropped aspirates everywhere), ignorantly adopted a spelling pronunciation. This error has since become the norm in British English, but Americans should not allow the more pompous and pendantic among us Brits to intimidate them into copying what is a British and not a North American mistake.
In all languages, some letters are silent. I know some Americans who do pronounce the ‘h’, but I do think that most do not. It is probably just how they were taught. The ‘English” language is full of words that do not sound like they are spelled, and are not spelled or sounded consistently. It can be a tough language to master.