English sound changes

The order here is something that works and seems to make sense to me, and is not necessarily historically accurate. In particular, after the Aus/RP split, comparable changes are next to each other, even if they didn’t happen at a similar time. This is largely based on Wikipedia’s article on the topic, but reformatted for convenience, sometimes reordered, has some uninteresting stuff cut out, and I think it’s generally more accurate. OTOH, it might also be less accurate.

Initial vowels:

FRONT:

iː	fleece, meat, near, sErious
ɪ	kit, fir, spIrIt happY, waitEd
eː	face, square
ɛ	dress, shErry

CENTRAL:

ə	probably less frequent than today
a	trap, bath, start, cArry

BACK:

ɑ	lot, cloth, north, pOrridge (Note: unrounded)
oː	goat, force
ʊ	strut, nurse, curry, ?foot
uː	goose, poor, jUry*

DIPHTHONGS:

əɪ	price, prize
əʊ	mouth, mouths
ɑʊ	palm /pɑum/, tall /tɑʊl/, thought, ?dance (words from A-N /ã/ probably usually fit in here, or they may long have alternated between /ɑu/ and /a/)
ɔi	choice

• I don’t know if /iu/ was changed yet to /juː/ or if that is a later change, but certainly “sure” /siuɹ/~/sjuːɹ/ and “sugar” /siugəɹ/~/sjuːgəɹ/ took part in early yod-coallesence. If not, the “jury” is /dʒiuɹɪ/ rather than /dʒuːɹɪ/, but it is of little significance.

(Note the distribution of /ɛɹ/ vs /aɹ/ was different from today’s distribution of NURSE with ‹er› and FAR in the standard speech of the day. e.g. “university” /iunivaɹsɪtɪ/ hence “varsity”)

Initial consonants

As PDE, except /ʍ/ is standard, but /ŋ ʒ/ are not.

Changes

Long vowels have shortened inconsistently in many eras, notably /uː/ → /ʌ/ before and after the foot/strut split, and /eː/ → /ɛ/ before the meet/meat merger (hence both meat (e.g. lead) and face (e.g. said).)

Pre-US

• ʊ → ʌ (exceptions after labials & before /l/)
• ng, mb → ŋ, m / _#
• early yod-coallesence:
  • tj, sj, dj, zj → tʃ, ʃ, dʒ, ʒ except (?in stressed syllables) before /uː/
• rhotic influence:
  • a → ɑː / _ɹ]_σ
  • ɑ → ɔː / _ɹ]_σ
  • ɛ, ɪ, ʌ → ɜː / _ɹ]_σ
• /ɑʊ/ monophthongisation:
  • ɑʊ → ɑː before labials, some nasals (e.g. aunt, dance, laundry)
  • ɑʊ → ɔː otherwise
  • a large number of cases that were ɑː have become ɔː subsequently for non-phonetic reasons, like laundry.

• a → æ (except in a few words, like “father” when → ɑː)

• Lowering of centre-starting diphthongs (this may have been delayed in happening before some voiceless consonants, hence Canadian Rising and the two allophones in the Scots Vowel Length Rule)
  • əɪ → äɪ (in most of Britain)
  • əɪ → ɑi (in some parts of South-Eastern England)
  • əʊ → äʊ (in most of Britain)
  • əʊ → æʊ (in those same parts of South-Eastern England)

• eː, oː → eɪ, oʊ except before /ɹ/

Phonology

FRONT:

iː	fleece, meat, near, sErious
ɪ	kit, spIrIt happY, waitEd
eː	face, square
ɛ	dress, shErry

CENTRAL:

ə	probably less frequent than today
ɜː	fir, nurse (only before /ɹ/)
a	trap, bath, cArry

BACK:

ɑ	lot, cloth, pOrridge (Note: unrounded)
ɑː	start, father, palm,
ʌ	strut, curry
ɔː	north, tall, thought
oʊ	goat [goʊt], force [foːɹs]
ʊ	?foot
uː	goose, poor, jUry*

DIPHTHONGS:

äɪ~ɑɪ	prize [äɪ~ɑɪ], price [äɪ~ɑɪ~əɪ]
äʊ~æʊ	mouths [äʊ~ɑʊ], mouth [äʊ~ɑʊ~əʊ]
ɔi	choice

After American/British split

British	American
Non-rhoticism: ɜːɹ → ɜː / _]σ ɑːɹ → ɑː / _]σ ɔːɹ → ɔː / _]σ eːɹ → ɛə / _]σ oːɹ → ɔə / _]σ iːɹ → ɪə / _]σ uːɹ → ʊə / _]σ
ɑ → ɒ
Trap-bath and lot-cloth splits	Lot-cloth split
æ → æː → aː / _[+fric -voice] or _[+nasal][-voice]; words which change vary between dialects
ɒ → ɒː → ɔː / _[+fric -voice]
In the /æː/ stage, trap/bath was exported to some parts (e.g. NYC) of America. Other parts (e.g. Boston) received it in the /ɑː/ stage.
America generally received the LOT-CLOTH split.
	Low vowel length-loss (father-bother merger) ɑː → ɑ ɔː → ɔ æː → æə~ɛə (to the extent that it exists) This reinforces the tense-lax distinction in non-low vowels, but length distinctions aren't completely lost.
ʍ → w	regional in US

After Australian/British split

Many of the changes marked “Australian” occurred in Britain, but are not a part of RP.

British	Australian	American
Development of dark /l/ (This appears to be a shared development, but apparently took place in the 19th century and had different specifics in most dialects.)
l → ɫ / in coda	l → ɫ / _	l → ɫ / (in some conditions)
oʊ → əʊ / _	Breaking oʊ → ɔʊ / _ɫ oʊ → əʊ / otherwise iː → ɪə / _ɫ iː → ɪi / otherwise uː → ʊə → uː / _ɫ (not NSW, Qld) uː → ʊʉ → ʉː / otherwise ɫ → əɫ / V[+long]_ (unless one of the above apply)
	ɪ → iː / unstressed word-finally and unstressed foot-finally if the next the next syllable is stressed and begins with /k g tʃ dʒ ʃ ʒ/	ɪ → i / unstressed word-finally
	ɪ → ə / unstressed syllables
	ə → ɪ / _(k, g, tʃ, dʒ, ʃ, ʒ, v)
	t → ɾ / V_V[-stress] (ish; probably happened in England and went over with the colonists)
	20th Century ɔə → ɔː Ongoing ɛə → ɛː ʊə → ɔː Early (before yod-loss) ʊə → oː / except after j, dʒ ʊə → ʉːwə / almost always otherwise; but see also in the Breaking section oə → oː	20th Century eə → eː, though the suffix -ary and related forms is /eɹiː/ when the “a” is pronounced Ongoing ɪə → ɪː Earlier: i, u, e → ɪ, ʊ, ɜ / _ɹ I think most AmE dialects also have o → ɔ / _ɹ and/or ɔ → ɑ / _ɹ Later also æ → ɛ / _ɹ in most AmE
Something	j → ∅ / σ[(s, z, l, θ)_V[+stress] sj, zj, lj → ʃ ʒ j~ɫj / otherwise (j~ɫj fluctuation is formality) ɫj → ɫi / after any segment after which coda-/ɫ/ is forbidden, e.g. failure [fæiɫiɐ] tj, dj → tʃ, dʒ	j → ∅ / σ[(s, z, l, θ, n, t, d)_
LOT-CLOTH split reversed properly	oː → ɔ / _ɹV[-stress] (ish) and in the same conditions that the LOT-CLOTH split occurred in. Hence, oral=aural [ɔɹəɫ] aust- = /ɔst/ ɔ → ɔː in “gone” and some derivatives	ɒ → ɔ / _[velar] (partial)
	æ → æː / _(n, m, g, ɫ)]σ unless (j, w) follows; and rarely _d; unless it’s a form of a strong verb.	æ → ɛə / _(n, m) and others depending on dialect

Stuff that needs to be included

• Jonathan's /nəi̯f/~/nəi̯vz/ thing
• AmE w stuff
  • ‹wa?_› /wə?_/ (squash, was, wash)
  • ‹war› /[wɔɻ/ (war, ward)
  • ‹t(ə)war› /tɔɻ/ (toward) .. same as above?
  • ‹[wor› /[wɻ/ (word)
  • ‹kwor› /kɔɻ/ (quart, quarter, *quarry)
  • ‹swor› /sɔɻ/ (sword, *swore)
• /ə/ in initial pre-vocalic syllable ~ /Ø/ (phonology /ˈfnɑləʤi/, surround /sɻau̯nd/, succomb /skəm/ (~scum??))
• syllabification, especially with cases of hiatus and ɻ
• ftn → fn (often /ˈɒfɪn/, soften /ˈsɒfɪn/)