Although stress falls predominantly on the penultimate syllable in nouns, antepenultimate and final syllable stress occur as well.
This follows from constraint interactions that occlude underlying stress from surfacing on any syllable to the left of the antepenultimate syllable.
Phonological lengthening in this case is never optimal and so any duration increase in an open antepenultimate syllable is a phonetic correlate of stress.
Since the foot containing a stressed antepenultimate vowel is bimoraic, there is no pressure to lengthen a stressed antepenultimate vowel.
In fact, while there is a remarkable duration difference between penultimate and antepenultimate syllable, the duration difference between antepenultimate and preantepenultimate syllable is much smaller.
They are identical to the stems, except for the - very frequent - group of verbs with antepenultimate stress, which appear with penultimate accent in the gerund.
When the lexical stress is antepenultimate, the emergent foot is also trochaic.
Two segments are truncated from the right edge of the imperfective, however, when the antepenultimate is a coronal followed by a high vowel (20c).