I am told on good authority that in schools of a certain denomination, and in those schools only, it is pronounced invariably as haitch, an oddity I cannot explain.
(Arnold Wall, The Queen’s English, 1958).
Perhaps it would be more accurate to say that the pronunciation aitch is hard to explain. The pronunciation of the letter h is one of Australia’s great social shibboleths: not just the way it is sounded as the first letter of a word, but more particularly the way the name of the letter itself is said. Some people say haitch; others call it aitch.
Although the spirit of our times is generous, forgiving, and tolerant, the choice between aitch and haitch can cause a good deal of anxiety and even hostility. Generally speaking, haitch is used by those educated in that part of the Roman Catholic school system that traces its origins to Ireland. Aitch is preferred by the rest. Some apostates deny their origins by abandoning haitch; but there is little traffic in the other direction. When I was a child, I was forbidden to say haitch; friends who said haitch were appalled that I ate meat on Fridays.
It is not at all surprising that the issue is so confused, since the pronunciation of h, when used as the initial letter of a word, has changed significantly over the past couple of millennia.
Although nothing much is certain in matters of language these days, the prevailing view, perhaps illogically, supports the pronunciation aitch. The OED2 gives it thus, and does not recognise haitch as an alternative. I say this is illogical, because it might be expected that the name of a letter of the alphabet would give a clue to the sound normally associated with it. In this matter, h, w, and y stand isolated from the rest of the alphabet, although the names of c, e, and g represent only the lesser part of the work done by those letters.
The issue is manifested in at least three ways: how is the name of the letter to be said; is the h sounded or not before a vowel; does a word beginning with h accept a or an as the indefinite article?
The sound represented by h was known in the Semitic, Greek, and Latin alphabets. In the Semitic it was a laryngeal or guttural aspirate, and remained so in the Greek and Latin. It passed from the Latin into the Germanic languages as a simple aspirate — that is, the sounded breath. It has been variously called ha, ahha, ache, acca, and accha. These earlier forms of the name explain the current form, and are clearly referrable to the sound represented.
In late Latin, and in early Italian and French, the aspirate gradually ceased to be sounded. In Italian, the h was progressively dropped in the written form of words, so that it is now absent from words which, in the French, retain it without sounding it: eretico (hérétique); storia (histoire); oribile (horrible); osteria (hôtel).
In Anglo-Saxon speech, h was always sounded, but from the Norman conquest the English pronunciation of words with an initial h gradually adopted the French manner; the English language has always been something of a trollop, pursuing advantage where it can. So for hundreds of years, the h was seen but not heard in ‘proper’ speech, at least in words which derive from the romance languages.
If the initial h of a noun or adjective is not sounded, the word naturally takes the indefinite article — an. At least from the eleventh century, then, it was natural to refer to an (h) istory, an (h)otel, an (h)our, an (h)onourable woman, an (h) umble person. The ambivalence of usage survives in words like hostler / ostler.
However, from the eighteenth century on, English usage began once more to aspirate the initial h. This coincides with the arrival of the Hanoverian monarchs, whose native language had always sounded the h. Thus words that had come into English via French began to be said with aspirated hs, although the change was gradual and patchy. Published in 1828, Walker’s Pronouncing Dictionary says that h is always sounded except in heir, heiress, honest, honesty, honour, honourable, herb, herbage, hospital, hostler, hour, humble, humour, humorous, and humorsome. Since that time, those underlined have also changed, but in the USA herb is still said with a silent h. Abominable was originally abhominable, at least from Wyclif’s time, and was explained as deriving from ab homine. It lost its h in pronunciation and then in spelling, and remained unaffected by the shift in the wake of the Hanoverian kings.
One of the oddest anomalies of this process is habitué, which is an unassimilated French word but which is generally spoken with a sounded h. By contrast, an (h)abitual liar is commonly said with a silent h, although it would be odd not to sound the h in habit. Homage is likewise anomalous.
As the shift back to aspirating the h was slow and illogical, it is not surprising that it provoked uncertainty in the choice of indefinite article. The choice is made the more difficult by a dread of dropping an aitch, which in many circles is a shocking thing if done incorrectly. The unhappy result is such usages as an hotel, an historic occasion, an hypothesis, an heroic effort, an hysterical outburst, etc. If the h is sounded, the result is silly and indefensible.
The rule is simple enough: a word which begins with a vowel sound takes an; a word which begins with a consonant sound takes a. So, an honest person, an hour, an heir, an unusual event, etc.; a hypothetical case, a historic occasion (but colloquially an ‘istoric occasion), a useful suggestion, etc. Before initials, the choice of article depends on the way the name of the letter is sounded: a UN resolution, an S-bend, an HB pencil, an X-ray, an MP. But if the collection of letters is a recognised acronym, the choice of article depends on how the acronym is said: a UNICEF official, an UNCITRAL official; a NATO resolution, a SALT meeting, a HoJo restaurant.
The anguish associated with sounding the initial h or not is common to all English speakers. One case where the h has crept in from error and remained is humble pie. Most of us have eaten it metaphorically; few have done so literally. It is a pie made from the entrails of a deer — the parts left over when those of higher station have taken what they want. The entrails of a deer are the umbles. The dish is umble pie. The h is an intruder, which preserves the meaning of the phrase, but disguises its origins.