A study examined a vowel alternation occurring in Philadelphia English and some dialects of New York State. The alternation is of [E] and [ae], and the study investigated the application of the [ae] Tensing Rule, more specifically in the interaction of [ae] Tensing with several principles of syllabification and grammatical organization. Issues addressed include the distribution's compatibility with the principle of Structure Preservation, the use of the notion of word cycle to explain asymmetry between words with Level 1 affixes and forms with Level 2 affixes, and comparative syllabification of Level 1 and 2 affixes. Two possible analyses of English Ablaut are offered. Data from Palestinian and Bedouin Hajazi Arabic are used to support the analysis' applicability beyond the scope of English. (MSE)