In Vytautas Ambrazas' Lithuanian Grammar it says "[U]nstressed [long] vowels in Standard Lithuanian show a tendency to be shortened and turn into half-long (sometimes even relatively short) tense vowels. These changes do not harm the phonological system: the contrast is not lost, but only modified. The occasional complete neutralization of the quantity of unstressed vowels can be explained only as a phenomenon of some other (mainly dialectal or sociolectal) phonological system." Some of the examples he gives are acc. sg. duoną vs. nom sg. duona, where the final vowels differ in quantity, and výrų vs. výru, where they differ in both quantity and -- apparently -- quality. What I haven't been able to understand is if the same applies to root vowels, like, e.g., the <e> in klias vs. keliù, or <a> in stãlas vs. stalù (I wonder what happened to the tildes). What say ye, native speakers?
 
One thing I noticed during the short time I actually had a Lithuanian teacher was that her version of [æː]/<e> in Petras was virtually identical to (my) Swedish allophone of <æ(ː)> before /r/, and from what I've gathered subsequently it probably wasn't a just peculiar idiolectal feature of hers. Now that we have people who know both Lithuanian and Russian on the list it seems like a good opportunity to ask about the realization of <я> between two 'soft' consonants in standard Russian and other varieties in words like пять. How close to standard Lithuanian [æː] would you say that this vowel is (as regards the quality of the syllabic nucleus)? And in what way(s) does it differ?
 
Urban