This study investigated the potential transfer of first language (L1) phonological processing unit to second language processing. English and Chinese phonology differ mainly in the complexity of their syllable structures. English phonology allows highly complex syllable structures, whereas Chinese has been characterized primarily as a core syllable language, i.e., its syllables typically consist only of a consonant and vowel (CV). This sharp contrast is hypothesized to entail different phonological processing units in the two languages, and to result in, through L1 transfer, the poor phonological awareness often observed in Chinese speakers learning English as a second language (ESL). This hypothesis was tested by examining the performance patterns of Chinese ESL fourth graders on phoneme deletion and phoneme isolation tasks. The results suggest that Chinese ESL children do seem to process an English syllable in terms of an intact core syllable plus its appendices due to L1 transfer. This gives support to a developmental account of subsyllabic division unit preference, which suggests that core syllable is universally preferred in the initial stages of language development, only after which speakers of different languages diverge in their division unit preferences due to linguistic characteristics of their respective L1s.

The presence of transfer suggested that Chinese ESL children performed differently on two item types--core-syllable items (requiring segmentation of an element within the core syllable) and non-core-syllable items (requiring segmentation of any appendices from the core syllable). As phonological awareness involves the ability to segment cohesive sound units, it was hypothesized that only performance on core-syllable items should represent phonological awareness. This hypothesis was tested by analyzing the item types' respective contribution to decoding skills. Phonological awareness has long been established as a strong predictor of decoding skills; thus the analyses served to test the two item types' respective criterion validity in tapping phonological awareness. The results confirmed the hypothesis. This implies that, methodologically, phonological awareness of Chinese ESL children could be more reliably measured if, in future studies, only core-syllable segmentation items are employed. Educationally, instruction in phonological awareness might emphasize core-syllable segmentation, which alone appears to reflect Chinese ESL children's phonological awareness.