Background and Aim: Learning Language is a skill which is acquired in early childhood. So, language gradually developed and new words and new structures slowly added to language knowledge. Hearing sense is the most important acquisition for of language and hearing disorder is a barrier for natural language acquiring .The purpose of this study is comparison between morphological and syntactic features of 4 to 5 years old severe to profound hearing impaired and normal children.

Materials and Method: This cross-sectional study performed on 10 normal-hearing children with mean age of 4-5, from Gazvin kindergartens and 10 hearing impaired children with similar IQ and age from Nioosha Rehabilitation Center. The language and non language information was received by spontaneous and descriptive speech, and questionnaire, respectively and for comparing syntax comprehension, Specific language impairment test was used. Then these results were compared between two groups.

Results: Difference between spontaneous speech and descriptive speech in hearing impaired child is just like normal child. These differences are that the number of utterance, the mean of lexical morpheme, functional morpheme in spontaneous speech is greater than descriptive speech but the mean length of utterance and richness of vocabulary in descriptive speech is greater than spontaneous speech. Mean of lexical morpheme, functional morpheme and richness of vocabulary related to morphological part and the number of utterance, the mean length of utterance and syntax comprehension related to syntax, in spontaneous and descriptive speech of normal children speech is greater than hearing impaireds`.

Conclusion: According to recent researches, compared with normal child, the hearing impaired child nearly never to reach equal level, and for this reason, training for this group is necessary. It is concluded that although these children have severe to profound hearing loss they are developing their language by auditory training, hearing aid, language therapy and educational assistance and they only have delay in period of language learning. In the other words, language growth of a 4-5 year old hearing impaired child is almost similar to a 3 year old normal child.

Background and Aim: The different studies in normal children and those with developmental language disorders showed the relationship between language and development of theory of mind (ToM). But, there is not agreement between authors about role of language aspects (lexicon, semantic, syntax, and pragmatics) in development of theory of mind. The aim of this review article was the study of relationship of aspects of language and development of theory of mind in normal children and those with developmental language disorder.

Methods: This study was a narrative review. The Persian and English published articles during 1995 to 2012 were searched from different websites [Cochreane library, Proquest, Springer, Ebsco, Sciencedirect, PubMed, Magiran and Scientific Information Database (SID)]. Keywords included theory of mind, language, syntax, syntactic complement, semantic, lexicon and pragmatics. Then, the titles and abstracts of the related articles about relationship between language and theory of mind were selected and studied.

Conclusion: The language is the most important factor and predictor of theory-of-mind development. Although, lexicon, semantics, pragmatics and general language were important in development of theory of mind, but most of the articles had stressed the role of syntactic complements (sentences with mental or communicative verbs) in its development in normal children and children with developmental language disorders. As syntactic complements are necessary prerequisites for development of theory of mind, particularly for false belief concept, it is predicted that focus on training these aspects in children with developmental language disorders can influence on both theory of mind development and language complexity.