This paper elaborates on Persian and English orthographic shared aspects to study the effects of L1 Persian on learning English as a foreign language. While there are some examples of letter and sound mismatches in the orthographic system of both languages, those of English are more complex than Persian. In order to see the effect of the mismatch between orthography and transcription, 40 Persian EFL learners were divided into two proficiency groups i.e., advanced and elementary, and their performance was examined on comprehension and production tasks. The learners’ production skills were checked via a list of 76 pseudo words requiring the learners to read them while their voices were recorded. After one week time interval, a comprehension test consisted of 34 items was administered, requiring the learners to listen and choose among the orthographic forms presented to them. It was hypothesized that being educated in L1 Persian comprising semi-opaque orthography system, the learners would tackle the English opaque graphemes better on the mismatches. However, it was observed that both elementary and advanced groups had difficulty learning English orthography system, showing almost no positive effect from L1. Only in rare cases more proficient learners performed better due to more schooling education in English.
