In order to make non-native children acquire academic Japanese language proficiency, we have found out that it is more effective to teach sentence patterns rather than vocabulary. Vocabulary in textbooks of content-area subjects is large, varying with subjects and grades, whereas the number of sentence patterns is limited and most of them are common to all textbooks.
Sentence patterns used in textbooks of content-area subjects at elementary school have been thoroughly examined by the authors. The series of textbooks of four subjects, namely "mathematics," "life (seikatsu)," "science" and "social studies" were selected from grade 1 to grade 6. Concerning the style of textbooks, it is pointed out that all textbooks have written language and spoken language, and that formal forms as well as informal forms are used in the same textbook. This means that the textbooks sometimes become too complicated for non-native children to understand.
The findings on sentence patterns are as follows:
1 Although "desu" is commonly used, a negative form "dewa arimasen" is seldom used. A past negative form "dewa arimasen desita" is not appeared in any textbooks.
2 The dictionary and volitional forms of verbs are often appeared at the end of sentence rather than in the middle of sentence.
3 Adjectives are used in the end of sentence and in front of nouns, but negative forms, past forms and past negative forms are not used.
4 A clause that modifies a noun is widely used.
5 Nominalization using "koto" and "no" is often used.
6 The passive voice is used well, especially in the textbooks of "science."
7 The sentence patterns that express personal relationship like "V te ageru/kureru/morau" is not used except in the subjects "life" and "social studies."
8 The sentence patterns that express personal feelings like "suki," "rasii" and "kamosirenaı" are not used except in the subjects "life" and "social studies."
Altogether 75 sentence patterns are designated as common sentence patterns. Out of 75, 32 were already taught as teaching items in the textbook, Isshoni Nihongo, that was published in 2002 by the authors.