Due to the phonetic differences between the Arabic and English languages, Arabic ESL students often experience difficulty pronouncing English vowels. Vocal quantity and vocal quality are the two phonetic parameters through which vowels are described. Vowel quantity refers to the duration of the phonetic segment symptomatic of the phonetic identity. On the other hand, vocal quality means knowing the precise way of articulating a vowel, which includes the shape of the lips, the position of the tongue in the vocal tract, or the nasalization of vowels. Each vowel has its own way of speaking. The Arabic language system is made up of 6 vowels while the English vowel system has 12 vowels. The main reason why Arabic ESL students tend to mispronounce vowels is because of this phonological difference. Furthermore, the extended vowel system of English shows a contrast between short lax vowels and tense long vowels; on the other hand, the vowel pattern of the Arabic language shows a contrast between short vowels and long vowels. Furthermore, the difference between the English and Arabic vowel systems depends not only on its size but also on the quality of the vowels. Another reason why Arabic ESL students face problems with English vowels is because of the nature of vowel systems: the Arabic language has a centrifugal vowel system while the English language has a centripetal vowel system, meaning that English vowels have the tendency to move to the center of the vowel space, which does not happen with centrifugal vowel systems such as the Arabic, Spanish, and Russian languages. Therefore, it is due to the distinct vocal quality, quantity, centrifugal and centripetal differences that Arab ESL students pro...... middle of paper ...... connected speech”, Antwerp papers in linguistics, 2002, 100, 77 -86. Shei, C., & Pain, H. “A collocational aid for an ESL writer.” Computer-Assisted Language Learning, 2000, 13, 167-182.Shehata, A.K. “L1 Influence on the Reception and Production of Collocations by Advanced Arabic ESL/EFL Learners of English.” Department of Linguistics and College of Arts and Sciences, 2008. Wang, J. T & Good, Robert L. “Corpus Study of Lexical Collocations of Verb Nouns in EFL Textbooks.” CELEA Journal, 2008, 31 (5), 1-11. Watt, D. “I don't speak with a Geordie accent, I speak, like, the Northern accent: contact involved leveling in the Tyneside vowel system.” Journal of Sociolinguistics, 2002, 6, 1, 44-63. Zughoul, M.R., & Abdul-Fattah, H. “Collocational translational strategies of Arab learners of English: A study of lexical semantics.” Babel, 2003, 49(1), 59-81.