H is a funny letter. In the English language, it almost always signals aspiration, the obvious exception being ‘herbs’, which our American friends pronounce ‘erbs’.
The letter itself is actually spelt ‘aitch’, and as a letter is pronounced without an ‘h’ sound. Most people, especially certain regions of England, routinely pronounce the letter ‘haitch’, and my daughter finds it particularly difficult to drop the ‘h’ when I test her spelling. ‘There’s no such letter as ‘haitch’, sweetie.’ ‘but Dad, listen to the word ‘house’, or ‘hello’, it must be ‘haitch’.
She’s right of course, it’s completely counter-intuitive. Your plosives, consonants which coincide with an expulsion of air, tend to begin with the sound they signify. Examples are b and p. Dental consonants, same thing really, examples being d and t. Your fricatives and labials – like f and and l – are harder for our mouth to form in order to start the word, so instead we prefer to prefix their names with a ‘e’ sound to get the syllable going.
The letter h, though, goes out of its way to avoid the sound that it signifies. In that sense it’s a bit like the letters w – ‘double-u’ – and y – ‘wye’ – which are also a bit maverick, but nobody ever mispronounces those two letters. Which leaves the letter h to glory in its own eccentricity. Hawesome.