This chapter is concerned with whether Korean preschoolers’ morphological awareness may be related to their speaking and reading comprehension skills across development. Person-specific verb modal suffixes of Korean are the main focus of interest in association with the use of a subject NP as a predictor for Korean children’s speech and comprehension skills. A longitudinal set of spontaneous speech data from two Korean toddlers was analyzed. Findings showed that the frequencies of person-specific suffixes were higher in null subject constructions than in overt subject structures across time points in both children. These results are important in light of the fact that Korean is discourse-oriented, allowing an NP to be ellipted if referentially accessible in a sentence and a discourse in speech, writing, and reading. It is proposed that morphological decomposition occurs as a result of activation resonance in the lemma within the spreading activation framework of semantic processing.