Phonological history of English consonant clusters
H-cluster reductions 
The h-cluster reductions are various consonant reductions that have occurred in the history of English involving consonant clusters beginning with /h/ that have lost the /h/ in certain varieties of English.
Wh-cluster reductions 
- The reduction of /hw/ to /h/ is the replacement of /hw/ with /h/ before the vowels /oː/ and /uː/ which occurred in Old English. This is due to the effect that rounded back vowels have on /h/, giving it velar and labial characteristics making /hw/ an allophone of /h/ before these vowels; the true phonetic /hw/ then eventually became perceived as this allophone of /h/ and no longer a phonologically distinct speech sound.
- The merger of /hw/ and /w/ is the merger of /hw/ (spelled wh) with /w/. It occurs in the speech of the great majority of English speakers. Notable dialects that retain the distinction include Irish English, Scottish English, and Southern American English. This occurred after the reduction of /hw/ to /h/ meaning that wh- is usually /w/ before orthographic a, e, i and y, but /h/ before orthographic o. (Orthographic a is usually phonologically /ɒ/ or /ɔː/ after /w/ in some varieties of English.)
Reduction of /hj/ 
The reduction of /hj/ is a process that occurs in some dialects of English that causes the cluster /hj/ to be reduced to /j/. It leads to pronunciations like /juːdʒ/ for huge and /juːmən/ for human; hew and yew become homophonous. It is sometimes considered a type of glide-cluster reduction, but is much less widespread than wh-reduction, and is generally stigmatized where it is found. Aside from accents with h-dropping, this reduction is in the United States found mainly in accents of Philadelphia and New York City; also in Cork accents of Hiberno-English. In some dialects of English[clarification needed], the cluster /hj/ (phonetically [çj]) has been reduced to [ç] so that hew and yew differ only by the initial consonant sound (i.e. [çuː] and [juː]).
hl-cluster, hr-cluster and hn-cluster reductions 
The hl-cluster, hr-cluster and hn-cluster reductions are three reductions that occurred in Middle English that caused the consonant clusters /hl/, /hr/ and /hn/ to be reduced to /l/, /r/, and /n/. For example, Old English hlāf, hring and hnutu became loaf, ring and nut in Modern English.
Y-cluster reductions 
Yod-dropping in English is the elision of the sound [j] in certain contexts following other consonantal sounds within the same syllable. The term comes from the Hebrew letter yod, which represents [j].
- After [tʃ, dʒ, j], for example chew [ˈtʃuː], juice [ˈdʒuːs], yew [juː]
- After /ɹ/, for example rude [ɹuːd]
- After consonant+/l/ clusters, for example blue [ˈbluː]
There are accents, for example Welsh English, in which pairs like chews/choose, yew/you, threw/through are distinct: the first member of each pair has the diphthong [ɪu] while the second member has [uː].
Many varieties of English have extended yod-dropping to the following environments, on condition that the [j] be in the same syllable as the preceding consonant:
- After /s/, for example suit [ˈsuːt]
- After /l/, for example lute [ˈluːt]
- After /z/, for example Zeus [ˈzuːs]
- After /θ/, for example enthusiasm [ɛnˈθuːziæzəm]
Yod-dropping in the above environments was formerly considered nonstandard in England, but today it may be heard even among well-educated RP speakers. In General American yod-dropping is found not only in the above environments but also:
- After /t/, /d/ and /n/, for example tune [ˈtuːn], dew [ˈduː], new [ˈnuː]
Glide retention in these contexts has occasionally been held to be a shibboleth distinguishing Canadians from Americans. However, in a survey conducted in the Golden Horseshoe area of Southern Ontario in 1994, over 80% of respondents under the age of 40 pronounced student and news without yod.
General American thus undergoes yod-dropping after all alveolar consonants. Some accents of Southern American English preserve the distinction in pairs like loot/lute and do/dew by using a diphthong /ɪu/ in words where RP has /juː/, thus [lut]/[lɪut], [du]/[dɪu], etc.
However, in words like annual, menu, volume, Matthew, continue, etc., where there is a syllable break before the /j/, there is no yod-dropping.
Some East Anglian accents such as Norfolk dialect extend yod-dropping not only to the position after /t/, /d/ or /n/, but to the position after nonalveolar consonants as well, so that pairs like pure/poor, beauty/booty, mute/moot, cute/coot are homophonous. Watchers of UK television are likely to be familiar with Bernard Matthews's description of his turkeys in his television advertisements as bootiful for beautiful.
In yod-pronouncing dialects, the spellings eu, ew, uCV (where C is any consonant and V is any vowel), ue and ui, as in feud, few, mute, cue and suit generally indicate /juː/ or /ɪu/, while the spellings oo and ou, as in moon and soup, generally indicate /uː/.
|Homophonous pairs after cj/j/r/sh/w/y|
|Homophonous pairs after l/s/th/z|
|Homophonous pairs after d/n/t|
|Homophonous pairs after other consonants|
Yod-coalescence is a process that changes the clusters [dj], [tj], [sj] and [zj] into [dʒ], [tʃ], [ʃ] and [ʒ] respectively.
This occurs in unstressed syllables in many varieties of English. Occurring in unstressed syllables, it leads to pronunciations such as the following:
It also occurs in some accents in stressed syllables as in tune and dune. Yod-coalescence in stressed syllables occurs in Australian, Cockney, Estuary English, Newfoundland English, and to a certain extent in New Zealand English, resulting in further examples as follows:
This can lead to additional homophony; for instance, in the case of /dʒ/, dew, due, and Jew come to be pronounced identically.
Yod-coalescence has traditionally been considered non-RP.
Other initial-cluster reductions 
Reduction of /wr/ to /r/ 
The reduction of /wr/ to /r/ is a reduction that causes the initial cluster /wr/ to be reduced to /r/, making rap and wrap, rite and write etc. homophones.
Old English had a contrast between /wr/ and /r/, the former characterized by lip rounding. In Middle English, the contrast disappeared and all cases of initial /r/ came to be rounded [rʷ].
Reduction of /kn/ to /n/ 
The reduction of /kn/ to /n/ is a reduction that occurs in modern English where the historical cluster /kn/ is reduced to /n/ making knot and not homophones.
All of the kn words stem from Old English forms beginning with cn-, and at the time all were pronounced with an initial /k/ before the /n/. These words were common to the Germanic languages, most of which still pronounce the initial /k/. Thus, for example, the Old English ancestor of knee was cnēo, pronounced /kne͡oː/, and the cognate word in Modern German is Knie, pronounced /kniː/.
Most dialects of English reduced the initial cluster /kn/ to /n/ relatively recently; the change seems to have taken place in educated English during the seventeenth century, meaning that Shakespeare did not have the reduction.
Reduction of /gn/ to /n/ 
The reduction of /gn/ to /n/ is the reduction of the initial cluster /ɡn/ to /n/. In Middle English, words spelt with gn like gnat, gnostic, gnome, etc. had the cluster /ɡn/. The humorous song The Gnu jokes about this, even though the g in gnu may actually have always been silent in English, since this loanword did not enter the language until the late 18th century. The trumpeter Kenny Wheeler wrote a composition titled "Gnu High", a pun on "New High".
Reduction of /s/ clusters 
Reduction of /s/ clusters is the dropping of /s/ from the initial consonant clusters with voiceless plosives (environments /sp/, /st/, and /sk(ʷ)/) occurring in Caribbean English. After the initial /s/ is removed, the plosive is aspirated in the new word-initial environment, resulting in pronunciations such as:
|spit||→ 'pit||([ˈspɪt]||→ [ˈpʰɪt])|
|stomach||→ 'tomach||([ˈstɐmək]||→ [ˈtʰɐmək])|
|spend||→ 'pen||([ˈspɛnd]||→ [ˈpʰɛn]) (also affected by final consonant-cluster reduction)|
|squeeze||→ 'queeze||([ˈskwiːz]||→ [ˈkʰwiːz])|
Final-cluster reductions 
|This section requires expansion. (February 2011)|
Final-consonant-cluster reduction 
|test||→ tes'||([tʰɛst]||→ [tʰɛs])|
|desk||→ des'||([ˈdɛsk]||→ [ˈdɛs])|
|hand||→ han'||([ˈhænd]||→ [ˈhæn])|
|send||→ sen'||([ˈsɛnd]||→ [ˈsɛn])|
|left||→ lef'||([ˈlɛft]||→ [ˈlɛf])|
|wasp||→ was'||([ˈwɑːsp]||→ [ˈwɑːs])|
Plum–plumb merger 
The plum–plumb merger is the reduction of the final cluster /mb/ to /m/ that occurs in all dialects of present English. In early Middle English, words spelled with mb like plumb, lamb etc. had the cluster /mb/.
Consonant-cluster additions 
Prince-prints merger 
The prince-prints merger is a merger of /ns/ and /nts/ occurring for many speakers of English. For them, "prince" and "prints" are homonyms as [prɪnts]. A [t] is inserted between the [n] and the [s]. Likewise the fricative [ʃ] often becomes [tʃ] after [n], so that "pinscher" and "pincher" are homophones.
These similar clusters may also merge:
- /nz/ and /ndz/ as in "bans", "pens" and "Hans" sounding the same as "bands", "pends" and "hands". The merged form being [nz]
- /mt/ and /mpt/ as in "dreamt" and "attempt". The merged form being [mpt].
- /ms/ and /mps/ as in "camps" and "hamster". The merged form being [mps].
Consonant-cluster alterations 
S-cluster metathesis 
For AAVE speakers with S-cluster metathesis the following words can undergo the following changes:
S-cluster metathesis is lexically determined.
The above pronunciations in fact have a long history, and all the metathesised forms have existed in English for around as long as the words themselves, with varying degrees of acceptance.
For example, the Old English verb áscian also appeared as acsian, and both forms continued into Middle English. The two forms co-existed and evolved separately in various regions of England, and later America. The variant ascian gives us the modern standard English ask, but the form "axe", probably derived from Old English acsian, appears in Chaucer: "I axe, why the fyfte man Was nought housband to the Samaritan?" (Wife of Bath's Prologue, 1386.) It was considered acceptable in literary English until about 1600 and can still be found in some dialects of English including African American Vernacular English. It is, however, one of the most stigmatized features of AAVE, often commented on by teachers. It also persists in Ulster Scots as /ˈaks/ and Jamaican English as /ˈaːks/, from where it has entered the London dialect of British English as /ˈɑːks/.
Scream–stream merger 
The scream–stream merger is the pronunciation of the consonant cluster /str/ as /skr/ occurring for some speakers of African American Vernacular English making "scream" and "stream" homophonous as /ˈskriːm/.
This phonological pattern in AAVE is a phonological pattern that's been mentioned from time to time, often by speech pathologists. Presumably the speech pathologists were concerned about this use of "skr" in place of standard English "str" because it was not clear whether the combination of sounds was an indication of a disorder or dialectal pattern. Still the scream–stream merger has not been observed or recorded in the literature nearly as often as other sound patterns. There are three possible reasons for this: (1) One is that because "skr" only occurs in positions where "str" can occur in general American English, there will be limited opportunity to produce the sound. (2) Secondly, the scream–stream merger may be viewed as a feature of the speech of young AAVE speakers that is not maintained in adult AAVE. (3) Thirdly, the scream–stream merger may be associated with AAVE spoken in certain regions of the United States.[original research?]
- Common words in which the /sk/ sequence occurs are given below:
In summarizing her research on the cluster, Dandy (1991) notes that the form is found in Gullah and in the speech of some young African Americans born in the Southern United States. She explains that the stream–scream merger is a highly stigmatized feature and that many of the students in her study who used it were referred to speech pathologists. She goes on to note the following about her research: "I also found a continuum that may indicate sound change in progress. If children said skretch for stretch, they probably have used the skr alternation in other words that contained the feature: skreet for street, skrong for strong, skrike for strike, skranger/deskroy for stranger/destroy. There were some who said skreet for street but did not make alteration on other words with that sound". (p. 44). Also, although Dandy does not make this point, it is important to note that the students' use of /skr/ may have been affected by the training they were getting from the speech pathologists.
See also 
- Phonological history of the English language
- Phonological history of English consonants
- Phonological history of English fricatives
- Wells, John C. (1982). Accents of English. Cambridge: Cambridge University Press. ISBN 0-521-22919-7 (vol. 1), ISBN 0-521-24224-X (vol. 2), ISBN 0-521-24225-8 (vol. 3) Check
- Gimson, A. C. (1980). An Introduction to the Pronunciation of English (3rd ed. ed.). London: Edward Arnold Publishers. ISBN 0-7131-6287-2.
- Ladefoged, Peter (2001). A Course in Phonetics (4th ed. ed.). Fort Worth, Texas: Harcourt College Publishers. ISBN 0-15-507319-2.
- Changes in Progress in Canadian English: Yod-dropping, Excerpts from J.K. Chambers, "Social embedding of changes in progress." Journal of English Linguistics 26 (1998), accessed March 30, 2010.
- Labov, William, Sharon Ash, and Charles Boberg (2006). The Atlas of North American English. Berlin: Mouton de Gruyter. ISBN 3-11-016746-8.
- Bauer, L. & Warren, P. New Zealand English: phonology in Schneider, E.W. "A handbook of varieties of English: Phonology, Volume 1", Mouton De Gruyter, 2005.
- The first recorded use of the word gnu in English dates back to 1777, according to the Merriam-Webster's dictionary.
- HLW: Word Forms: Processes: English Accents
- List of AAVE features contrasting with MUSE
- Ebonics Notes and Discussion
- Phonological Features of African American Vernacular English
- Online Etymology Dictionary