Anatoly Liberman suggests a conflation of two obsolete orderings of the alphabet, one with H immediately followed by K and the other without any K: reciting the formers ..., H, K, L,... as [...(h)a ka el ...] when reinterpreted for the latter ..., H, L,... would imply a pronunciation [(h)a ka] for H.

Use in writing systems
English
In English, ⟨h⟩ occurs as a single-letter grapheme (being either silent or representing the voiceless glottal fricative () and in various digraphs, such as ⟨ch⟩ , , , or ), ⟨gh⟩ (silent, /ɡ/, /k/, /p/, or /f/), ⟨ph⟩ (/f/), ⟨rh⟩ (/r/), ⟨sh⟩ (), ⟨th⟩ ( or ), ⟨wh⟩ (/hw/). The letter is silent in a syllable rime, as in ah, ohm, dahlia, cheetah, pooh-poohed, as well as in certain other words (mostly of French origin) such as hour, honest, herb (in American but not British English) and vehicle (in certain varieties of English). Initial /h/ is often not pronounced in the weak form of some function words including had, has, have, he, her, him, his, and in some varieties of English (including most regional dialects of England and Wales) it is often omitted in all words (see ⟨h⟩-dropping). It was formerly common for an rather than a to be used as the indefinite article before a word beginning with /h/ in an unstressed syllable, as in "an historian", but use of a is now more usual (see English articles § Indefinite article). In English, The pronunciation of ⟨h⟩ as /h/ can be analyzed as a voiceless vowel.
Other representations
See also
American Sign Language grammar
List of Egyptian hieroglyphs#H

References
External links

 The dictionary definition of H at Wiktionary
 The dictionary definition of h at Wiktionary
Lubliner, Coby. 2008. "The Story of H." (essay on origins and uses of the letter "h")