Morpheme refers to the study of the internal structure of words as well as the smallest functional component of a morphological complex word. Morphological processing, which is always unconscious, proposes that complex words are decomposed into their constituents that are based on symbolic rules. In recent years, the pattern of morphological processing of the second language learners has gained its popularity among researchers. In the domain of English morphological processing, researchers discovered that there are significant differences between English native and non-native speakers as well as between inflectional and derived morphology, though the amount of research for L2 studies is relatively small. The dual-mechanism model is consisted of two distinct representational systems and the corresponding processing mechanisms for morphologically complex words; the whole word pattern and the rule-based structured pattern. The native speakers tend to use a rather stable and efficient rule-based pattern, whereas the non-native speakers tend to face more problems and depend mainly on the whole word system. This article introduces a series of latest studies in respect to the pattern of morphological processing as well as the differences between L1 and L2 speakers in detail, provided that the possible causes underlie the L1 and L2 disparity and the possible factors involved that may influence the process in question. On the other hand, the inflected and derived words are the most important constituents of the English word system. Furthermore, researchers proved that the native and non-native speakers used the derived and inflected words in a significantly different way. As a result, this article compares the disparity of the morphological processing patterns between native and non-native speakers from two different perspectives, and identifies and exposes the critical debated questions. However, due to the dearth of L2 research, there are still many questions that remain unclear and require further research and thorough investigation.