Orthographic Depth and Spelling Acquisition in Estonian and English: A Comparison of Two Diverse Alphabetic Languages

In this study, we investigated the link between the orthographic transparency of a language and the ease or difficulty of acquiring spelling proficiency in that language. The two languages compared are English, with a highly irregular sound-to-print correspondence, and Estonian, a Finno-Ugric language that has one of the most highly regular sound-to-print matches among alphabetic languages. Our study finds Estonian students able to use their early knowledge of stable letter-sound correspondence to attain a high level of spelling proficiency as early as first grade. English students progress more slowly along a predictable pattern of acquiring proficiency based on increasingly more difficult word features. The final indication is that progress in spelling is highly dependent on the orthographic depth of the language being studied.