International Journal of Linguistics ISSN 1948-5425 2016, Vol. 8, No. 1 www.macrothink.org/ijl 15 The Phonological Alternations in the Noun of Instrument (fɪʕɑ:l) Ayman Yasin Coordination Unit for Service Courses Princess Sumayya University for Technology, P.o.Box 1438 Al-Jubaiha, Amman 11941 Jordan Tel: 962-798-071-567 E-mail: a.yasin@psut.edu.jo Mahmoud Al Qudah Princess Sumayya University for Technology, P.o.Box 1438 Al-Jubaiha, Amman 11941 Jordan Tel: 962-796-702-830 E-mail: mq@psut.edu.jo Helen Al-Gweiri The World Science and Education Univerity, Tabarbour, Amman, Jordan Tel: 962-799-274-763 E-mail: hellenahmad@yahoo.com Received: February 8, 2016 Accepted: February 19, 2016 Published: February 22, 2016 doi:10.5296/ijl.v8i1.0909 URL: http://dx.doi.org/10.5296/ijl.v8i1.0909 Abstract The present paper aims at examining Arabic phonological alternations that occur when deriving the noun of instrument with the pattern fɪʕɑ:l from strong and weak trilateral verbs. To this end, the researcher chose 32 nouns of instrument from Al-muʕjam al-wasi:T (2001) that represent the strong and weak trilateral verbs evenly. The findings of the present study show that the nouns of instrument which are derived from strong trilateral verbs undergo systematic alternations since the non-high vowel /ɑ/ after the first radical alternates to the high vowel /ɪ/ and the short vowel after the second radical /ɑ/ corresponds to the long vowel /ɑ:/. Nouns of instruments which are derived from weak trilateral verbs can be classified into three classes: class one undergoes a systematic alternation where the non-high vowel /ɑ/