Abdollahnejad, Elias2020-11-202020-11-202020-11-192371-2643http://hdl.handle.net/1880/112769This study investigates the qualitative and quantitative features of English tense (/i: & u:/) and lax (/ɪ & ʊ/) vowels in the L2 production of advanced L1 Persian speakers. The first two formants (F1 & F2) are used to determine the spectral quality of vowels, while the vowel length (in milliseconds) represents the vowel quality. Unlike English, which has two high front (/i:/ & /ɪ/) and back (/u:/ & /ʊ/) vowels, Persian has only one high front vowel /i/ and one high back vowel /u/. Considering this difference, the main questions of this study are whether L1 Persian speakers have separate representations of English tense and lax vowels in their L2 phonological inventory and, if yes, whether they differentiate these vowels based on their qualitative and/or quantitative features. According to the Equivalence Classification Hypothesis (Flege, 1987), L1 Persian speakers are expected to assimilate/merge English front vowels /i: & ɪ/ to their existing L1 single front vowel /i/ and English /u: & ʊ/ to their existing single Persian back vowel /u/. A group of ten female advanced L1 Persian speakers of English are compared with a control group of ten female native English speakers in their production of these vowels in open and closed syllables. Results show that while both quality and quantity are used by English speakers, the Persian speakers have difficulties in acquiring this distinction in their L2 English on both measures. However, the difficulty seems to be mostly in the acquisition of L2 phonetic features (i.e. gradual) than phonological ones (i.e. categorical).engLinguisticsFarsiPersiantense vowelslax vowelsvowel qualityvowel quantityjournal article10.11575/PRISM/38400