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) through a correlation study. Samples of writings of both groups were studied and analyzed through affixation principles and 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 its (.75) coefficient determination (shared variance) exists between two groups’ performance and the result of the study on the basis of oft-used affixes bears approximately a close resemblance to the findings by Fry and Kress( 2006), Hoing et al. (2000), Bauer et al.(1982), and White et al. (1989). Finally the implications of the study were taken into account.