The present paper aims at examination and recognition of the relationship between those orthographical errors found in compositions and Kurdish-Language students which result in phonemic processes. Considering the fact that phonemic and conversational differences existing in Kurdish language have influence on written forms of Persian words and lexicons, therefore, one of the main problems in Persian-language compositions written by Kurdish speakers of primary schools is the existence of orthographical errors pertaining to phonemic processes such as deletion. From the viewpoint of psychology of language, the influence of phonemic processes in instances such as hearing sensitivities arising from the weakness in hearing memory, visionary, and weakness in visual memory are being appeared, and bilingualism also makes an impact on this phenomenon. Certainly, one can say that orthography is a vivid, dynamic and semi-active process in writing and while a person hears a word, he writes it down as well. However, students while writing compositions, they are thinking about words and creating them as well, and they write appropriate words which are suitable to the text and they should apply words which are orthographically correct to apply. The method of the present research is of descriptive-analysis nature by following Salinger Error Analysis Method (7332). The statistical society of it consists of Kurdish speaking students in Sap Pol Zahab city and through using the sampling method of one-phase clustering method, 731 compositions have been analyzed and examined and the specified results have been found; Acquired results are as follows: 7 – Most students showed visual memory weakness in writing words whose morphological construction in Persian language have no one to one correspondence to their alphabet.2 – In writing words whose morphological construction possesses alphabets whose phonological producing place are not the same, they also showed hearing sensory weakness.