Although common in most regions of England and in some other English-speaking countries, and linguistically speaking a neutral evolution in languages, H-dropping is often stigmatized as a sign of careless or uneducated speech, due to its strong association with the lower class.
The reverse phenomenon, H-insertion or H-adding, is found in certain situations, sometimes as an allophone or hypercorrection by H-dropping speakers, and sometimes as a spelling pronunciation or out of perceived etymological correctness.
In Old English phonology, the sounds [h], [x], and [ç] (described respectively as glottal, velar and palatal voiceless fricatives) are taken to be allophones of a single phoneme /h/.
As a result, in the standard varieties of Modern English, the only position in which /h/ can occur is at the start of a syllable, either alone (as in hat, house, behind, etc.
The phenomenon of H-dropping considered as a feature of contemporary English is the omission, in certain accents and dialects, of this syllable-initial /h/, either alone or in the cluster /hj/.
The pronoun it is a product of historical H-dropping – the older hit survives as an emphatic form in a few dialects such as Southern American English, and in the Scots language.
Puns which rely on the possible omission of the /h/ sound can be found in works by William Shakespeare and in other Elizabethan era dramas.
It is suggested that the phenomenon probably spread from the middle to the lower orders of society, first taking hold in urban centers.
H-dropping in English is widely stigmatized, being perceived as a sign of poor or uneducated speech, and discouraged by schoolteachers.
It may also be used when any vowel-initial word is emphasized, so that horse /ˈɔːs/ (assuming the dialect is also non-rhotic) and ass /ˈæs/ may be pronounced [ˈˈhɔːs] and [ˈˈhæs] in emphatic utterances.
[11] Sandhi phenomena may also indicate a speaker's awareness of the presence of an /h/ – for example, some speakers might say "a edge" (rather than "an edge") for a hedge, and might omit the linking R before an initial vowel resulting from a dropped H. It is likely that the phonemic system of children in H-dropping areas lacks a /h/ entirely, but that social and educational pressures lead to the incorporation of an (inconsistently realized) /h/ into the system by the time of adulthood.
Processes of H-dropping have occurred in various languages at certain times, and in some cases, they remain as distinguishing features between dialects, as in English.
Also the Low Saxon speaking area around Zwolle, Kampen, Steenwijk, Meppel and Hoogeveen have h-dropping, the former island of Urk has it too as do some regions in Groningen.
French, Spanish, and Romanian have acquired new initial /h/ in medieval times, but they were later lost in the first two languages in a "second round" of H-dropping.
It is hypothesized in the laryngeal theory that the loss of [h] or similar sounds played a role in the early development of the Indo-European languages.
Modern Hebrew is in the process of losing /h/; the phoneme is either replaced by /ʔ/ (word-initially) or entirely absent (in all other positions) in the speech of contemporary young speakers.
Many dialects of Persian spoken in Afghanistan (i.e. Dari) do not realize the phoneme /h/, except in high-prestige literary words or in hyper formal speech.