Do linguists recognize a distinction between the "rules" of a dialect on the one hand and its individual pronunciation "quirks" on the other? Is there a term for this phenomenon? Is it considered merely a variation on regional preferences for certain words over their synonyms (e.g., rubbish vs. garbage), or is there something else at play here?
I would say that linguists in general tend to consider the entire lexicon of each language/dialect/sociolect/regiolect/idiolect as a more or less complete system unto itself. This system may share or not share more or fewer characteristics with other like systems, but they are ultimately separately existing systems.
These systems are all basically phonetically based, though. Writing complicates matters, but it doesn’t change the basics of the systems: they are at their inmost based on spoken sounds.
As an American, you can learn to pick up RP quite easily to the extent that RP mirrors American phonemically. If the underlying phonemes of a word are the same, a simple translation or transposition from one phoneme-based system to another is all that is needed. But in any case where the underlying phonemic structure differs, there is no other way than just to learn by rote. Lieutenant is one such word: it is simply ‘sound-spelt’ differently in the two dialects. The fact that the codified and standardised conventions of our writing system has them spelt the same way makes it less obvious to draw this conclusion, but American and British ‘lieutenant’ are really two different words, just like ‘truck’ and ‘lorry’ are. Of course, it is easier to remember in a practical situation that a word for something in a foreign system is almost, but not quite, the same as in your own system, so there is a cognitive difference. But as far as direct transposition from system to system goes, there is no difference: something is either mappable or it isn’t.
I don’t think there is really a term for this, except perhaps in the guise of pointing out that words that aren’t mappable constitute isoglosses between the systems (which isn’t really what you’re looking for). With all related languages, there are words that map perfectly between systems, and there are words that don’t—the latter category being made up of words that, once you know them, can be retrofitted into almost mapping, and words that do not match at all. But for all languages, this is a continuum.
Between American and British English, the vast majority of the language maps, and a minority of words don’t. Between languages like Spanish and Portuguese or Ukrainian and Russian, a good percentage of the words map, but many don’t. Between Danish and German, a fair few roots are mappable, but the majority of the morphology—and hence of the complete surface forms of words—are not. Between Icelandic and Dutch, virtually nothing is mappable, though many words still fall in the ‘lieutenant’ category of words that are close enough to be recognised as being related to each other. And between Greek and Swahili, virtually everything is neither mappable nor recognisable.
No, there cannot be. Phonemic /e/ at the end of a word in English can only occur as a phonetic falling diphthong [ej], as in say or they. That’s why those have a ‹y› in our spelling today, and why sleigh has an ‹i› in it.
And unstressed /ɛ/ will soon enough go the way of all things, despite what bokeh enthusiasts would have you believe. (Same with the meh-sayers.) Because English phonotactics forbid an open /ɛ/ at the end of the word, those will therefore soon enough become either a phonemic schwa /ə/ — or else become a close vowel like /e/ or /i/ phonemically and so one with the characteristic falling phonetic diphthong [ej] or [ij] required by English phonotactics.
I therefore little doubt that the word currently spelled bokeh will end up /ˈbokə/ just like the boca heard in the city of Boca Raton, Florida, to rhyme with mocha.
The other two possibilities are for bokeh to wind up rhyming either with hokey or else with hockey. This would be like how Spanish chile which ends with /e/ becomes in English chili which ends in /i/.
Only if the second syllable became stressed could bokeh become /boˈke/ or more likely /bəˈke/, which is the sort of thing you get when in English you pronounce the Spanish word olé under English phonotactic rules.
Whatever happens to words like bokeh as they assimilate to English, they will need to be respelled to use a spelling similar to whatever words they end up rhyming with in order for them to be predictably pronounced by monoglot English readers.
Probably spelling what is now commonly rendered bokeh in English as boka would have been better from the get-go.
Best Answer
You're close. It depends on the stress of the syllable before the -ative. If there is primary or secondary stress, then you have an unstressed a in the -ative. Otherwise, the a would be stressed and get its full /ei/ sound. Note that some words have different pronunciation patterns in different dialects.
Here is a link to all the -ative words in the COCA.