Compared to English, there is a difficulty in reading Chinese, Korean and Japanese text, because there are no relatives in these languages. Since relative pronouns and conjunctions appear at the beginning of clauses in English text, readers understand structure of sentence before comprehending the meaning of it. In the case of Japanese text, readers literally follow the meaning of sentence and then construct the relationship between segments by postpositional particles. Sentences in engineering textbooks include long and complex sentences to explain complicated matters, compared to non technical writing such as novels and essays. The authors propose the adoption of using Japanese quotation marks,「 」which are at present rarely used in engineering textbooks to show clauses or long phrase.