Phonological awareness may be influenced by differences in the characteristics of the items studied. This hypothesis is considered particularly applicable to Arabic, which is a diglossic language. This study examined the impact of phonemic position and the affiliation of the items between spoken and standard languages on phonemic isolation tasks. The data were obtained from 310 native Arabic-speaking kindergarteners and first graders and revealed that for simple and complex monosyllabic pseudo-words, isolating initial phonemes was more difficult than isolating final phonemes. In addition, the items in the spoken language were easier than the items in the standard language for the children at both grade levels. Thus, certain phonological features of the standard language may not be sufficiently developed even after entrance to school, which may explain certain difficulties in reading development in Arabic. The results are discussed in relation to previous findings.