Abstract: Idioms, one of figurative speeches, are special in semantic structure. The acquisition of idiom comprehension is based on a
number of abilities, such as cognitive, linguistic, and pragmatic competence. Thus, comprehending figurative language usually causes
particular difficulties for young children and atypical children. The reason comes from the lack of abilities in semantic analysis and
inference form context, which are rooted from theory of mind and executive control function. The rare researches show that the failure in
processing the linguistic context in which the idiom is embedded is the main reason for children can't assess the idioms' meaning.

Key words: idioms；atypical children；semantic analysis；context process；ToM；ECF