This mini-corpus, cross-linguistic, comparative, and norm-referenced study intends to render the most frequently and oft-used affixes in the written descriptive tasks in the performance of English language materials developers (ELMDs) and Iranian English language undergraduates (IELUs). Samples of writings of both groups were studied and analyzed through affixation principles. The frequency of nearly 63 affixes both inflectional and derivational morphemes was taken into account. The statistical analysis showed a highly significant correlation (.86) with (.75) coefficient determination (shared variance) between the performance of IELUs and ELMDs. The result of the study bears approximately a close resemblance to the findings by Bauer et al.(1982), Fry and Kress (2006), Honig, Diamond, Gutlohn, and Mahler (2000), and White, Sowell, and Yanagihara (1989). Finally, the implications of the study were taken into account.
