The present study used the lexical decision (making YES/NO decision) and the vocalization (naming) paradigms in two reaction time experiments to examine the cohesiveness of onset-rime and peak-coda in the syllable structure of English lexical items. The aim was to study the effect of sonority hierarchy of liquids, nasals and obstruents on the accurate and rapid identification and naming of CCVCC words and pseudowords in relation to the spelling performance of 222 grades 4, 5 and 6 students. In the onset-rime lexical decision and naming tasks nasals were processed faster than the liquids and the obstruents. In the peak-coda lexical decision and naming the obstruents were processed faster than the liquids and nasals. The reaction time results suggest relationship with the spelling of English words even though the significant main effects of grade, spelling performance, mode of response and lexicality of the stimulus items need to be interpreted in the context of statistical interactions.