This study sheds light on the problems that Arabs have with the pronunciation of some consonant sounds, including /p/, /v/, /θ/ and /ð/ as well as consonant clusters. It investigates the reasons of Arab students' confusion between /p/ and /b/, /v/ and /f/, /θ/ and /s/, as well as /ð/ and /z/, in addition to their tendency todeclusterization, inserting a vowel sound inside a consonant cluster. Moreover, these two pronunciation problems are investigated in light of L1 transfer. The research adopts the descriptive and analytical method with the use of observation at one of Syrian secondary schools. The results show that manystudents mispronounce the sound /p/, and a few of them the sound /v/, replacing them with /b/ and /f/ respectively, which can be attributed to the lack of corresponding sounds in their mother tongue, Arabic. However, many students mispronounce both /θ/ and /ð/ although they do exist in the inventory of Arabic sounds because of the impact of vernacular dialects and diglossia. Finally, students fail to pronounce consonant clusters correctly, inserting a short vowel in between because of the difference in the phonological rules of both their L1 and L2. Accordingly, a number of recommendations are proposed to encourage both school students and teachers to avoid such errors.

Consonant sounds, Consonant clusters, mispronunciation, L1 transfer, Syrian secondary schools