Especially in pre-academic ESL/EFL instruction, the common strategy is to devote considerable instructional time to rules and patterns of word stress assignment, and attention to principles of vowel reduction. As noted in earlier posts, some of that emphasis is due to the fact that many acquire pronunciation through reading--not speaking and listening-- and need good strategies for figuring out word stress and vowel reduction, especially with technical terms. With the advent of good audio sources for pronunciation, at least some of the need for essentially "phonic" decoding has been lessened. Flege and Bohn's 1989 research inked above came to the striking conclusion that " . . . L2 learners acquire [word] stress placement and vowel reduction in English on a word-by-word basis." In that study, the vowel quality of the vowels in the words that were being learned appeared to be impervious to alteration or enhancement once the word had been assigned meaning and use conditions. If that is indeed the case in general--and that has certainly been my experience in working with stress and vowel reduction in conversational language, especially with intermediate-level and above, then the key to developing accurate pronunciation at least at the segment-level seems to be experiencing and anchoring the felt sense of a word as a whole, not as simply a token of a pattern or process. Now the pattern of the stress assignment or vowel reduction involved may generate to other new words in some manner, but basically, those aspects of the word that are learned as part of the initial, overall configuration, which includes any number of factors in addition to those that are sound-related, are highly resistant to change later. In other words, the brain of the learner apparently grasps whatever pronunciation of the new word is immediately available or possible-- and then doesn't look back much or continue trying to approximate the L2 target much further, if at all. In a word, we do appear to learn the pronunciation of the language . . . one word at a time.