7. The method of claim 1 , wherein the extracting includes: searching an inflected word serving as a head word by using the information on the dependency relationship in the source-language sentence; forming a subcategory frame of the inflected word by tracking a word and syntax that depends on the inflected word; searching parallel-translation of each word and syntax of the source-language sentence in the target-language sentence; and extracting translation knowledge on the subcategory of the inflected word by connecting the parallel-translation of the word and syntax to the subcategory frame of the inflected word.
7. The method of claim 1 , wherein the extracting includes: searching an inflected word serving as a head word by using the information on the dependency relationship in the source-language sentence; forming a subcategory frame of the inflected word by tracking a word and syntax that depends on the inflected word; searching parallel-translation of each word and syntax of the source-language sentence in the target-language sentence; and extracting translation knowledge on the subcategory of the inflected word by connecting the parallel-translation of the word and syntax to the subcategory frame of the inflected word. 8. The method of claim 7 , wherein the parallel-translation of the word and syntax is expressed as a form of feature structure.