Finite is pronounced ['faɪnaɪt] while infinite is pronounced [ˈɪnfɪnɪt]. So why is the vowel in the first syllable of 'finite' different from the vowel in the second syllable of 'infinite'?
OK, it's not because of Trisyllabic Laxing, I made an erroneous assumption which I deeply regret.
The answer is actually simple. As Luigi Burzio explains in Principles of English stress, the reason boils down to English stress patterns.
The diphthong [aɪ] (as in bite) almost never occurs in unstressed syllable. The diphthong [aɪ] has a systematic relationship with the short vowel [ɪ]. This relationship is also reflected in Trisyllabic Laxing; divine-divinity, derive-derivative and in drive-driven etc.
From this relationship, we can infer a general rule of thumb that [aɪ] will only occur in stressed syllables and when that syllable gets unstressed, [aɪ] will shorten to [ɪ].
Now when you prepend the prefix in- to finite, the primary stress moves to the prefix in- because it's a stress-bearing affix.
- In + f[aɪ]nite → inf[ɪ]nite
- In + p[əʊ]tent → imp[ə]tent
- In + m[aɪ]grant → imm[ɪ]grant
- In + f[eɪ]mous → inf[ə]mous
Another example would be cycle-bicycle:
- Bi + c[aɪ]cle → bic[ɪ]cle
There are exceptions, however. Luigi Burzio has explained all the rules and exceptions thoroughly in his book. One of the many exceptions is the prefix un- which doesn't take primary stress, for instance, unab[eɪ]ted.
Latinate words in English tend to be stressed on the penultimate (second last) syllable unless that syllable is short, in which case the primary stress falls on the antepenult (third last syllable) but not on preantepenult (fourth last) as far as I know. That's why impossible, implausible, incredible etc., are stressed on the antepenult.
𝑇𝐿;𝐷𝑅
In General American English, don't is pronounced /doʊnt/ while in Southern Standard British English, it's pronounced /dəʊnt/.
In don't you, the /t/ of don't and /j/ of you coalesce to /tʃ/. The process is called assimilation.
𝐸𝑥𝑝𝑙𝑎𝑛𝑎𝑡𝑖𝑜𝑛
Assimilation makes nearby sounds more similar to each other. The kind of assimilation in don't you is called coalescent assimilation.
When /j/ comes right after /t/, there's a tendency to assimilate them to /t͡ʃ/. The /t/ is normally articulated at the ridge right behind the top teeth (alveolar ridge), but when it comes before a /j/ (which is articulated further back in the mouth—at the hard palate), it's usually pronounced /t͡ʃ/. What happens here is that the /t/ is articulated further back in the mouth in anticipation of the following /j/, so it becomes /t͡ʃ/ i.e. they coalesce to /t͡ʃ/.
The following sounds often coalesce:
- /t/ and /j/ coalesce to /t͡ʃ/ (as in posthumous)
- /d/ and /j/ coalesce to /d͡ʒ/ (as in education)
- /s/ and /j/ coalesce to /ʃ/ (bless you is sometimes pronounced bleshoo)
- /z/ and /j/ coalesce to /ʒ/ (as in vision)
You might have noticed that in informal situations (mostly in chatting platforms), most people write contractions such as dontcha, whatcha, gotcha etc. These are the phonetic spellings of the assimilated forms.
- dontcha → don't + you
- whatcha → what + you
- gotcha → got + you
- betcha → bet + you
Similarly, 'did you' is often pronounced as /dɪdʒjuː/ because /d/ and /j/ assimilate to /d͡ʒ/.
I wonder is this something specific to American accent?
No. It's not restricted to American English.
Best Answer
TL;DR
Your friend is incorrect. It's not *tpelf with p, but tƿelf with ƿ—Wynn—which was the Old English (OE) letter to represent the phoneme /w/.
So twelve was tƿelf 1. Twenty was tƿēntiȝ 2. Two was tƿā 3.
Historical prelude to W
The letter that looks like a P is actually:
It's called Wynn which was a runic letter in Old English alphabet for the phoneme /w/. 'Wynn' literally means 'joy' and itself would've been written:
It's how Old English4 looked like (Beowulf):
Ƿ can be seen in the first line of 'Beowulf'. The first word is HǷÆT ('what').
The OE alphabet was based on the Latin alphabet. The Latin alphabet of the time did not have the letter ⟨w⟩, therefore OE scribes borrowed the rune ⟨ᚹ⟩ to represent the /w/. They adapted it as the Latin letter Wynn ⟨ƿ⟩.
It was still in use after the Norman Conquest, but was soon supplanted by uu (whence the name double-u) under the influence of Normans. Middle English (ME) scribes adopted a practice of writing certain letters using a sequence of a particular short downstroke of the pen/quill, called a minim. A dotless i was a single minim and looked like:
In particular, minims were used for the following letters:
This is how minims looked like:
And the word 'minim' itself would've been written:
In Middle English period, w was written with four identical minims i.e. as two U's (ʅʅʅʅ), so they called it double-u and the name stuck. It would've been written something like:
Early printers used two V's (vv) for the double-u and was later on revamped to a single letter w.
In Present day English, it's still called double-u.
𝐍𝐎𝐓𝐄𝐒
The f changed to a v because of intervocalic fricative voicing. Old English had a phonetic property called 'intervocalic fricative voicing', whereby non-velar fricatives—/s, f, θ/—became voiced when they were flanked by two vowels, or a vowel and another voiced consonant (i.e. OE didn't contrast voiced and voiceless fricatives). So bath was bæþ and would've been pronounced [bæθ], bathe was baþian and would've been pronounced [ˈbɑðiɑn]. Wolf was wulf and would've been pronounced [wulf], wolves on the other hand was wulfas and would've been pronounced [ˈwulvɑs]. I've explained it in this answer to another question. tƿelf was followed by a suffix beginning with a vowel which changed the f to a v.
ȝ is called Yogh and it represented the /j/ ('y') sound in this instance: /ˈtweːn.tij/
The W in 'two' was pronounced in Old English. The W was lost somewhere between Old and Middle English. There was a sound change through which a /w/ was lost in the environment of a preceding [s] or [t] and a following back vowel ([ɒ ɔ o ɑ u] etc). So 'two' was tƿā and it was pronounced /twɑː/ in Early Middle English, it became /twoː/ and then it lost the /w/ and became /toː/ (the vowel /oː/ was shifted to /uː/ because of the Great Vowel Shift). I have explained the W's in 'sword', 'swore' and 'two' in this answer
Old English was much more phonetic and highly inflected than Modern English. Every word was spelt how it was pronounced, there were no silent letters in OE.
References: