中文摘要：

现实性和非现实性这一对语法范畴的划分并不是绝对的,两者之间是可以互相转化的。将来时标记和情态都属于非现实的语法范畴,因而在汉语史上都有当作非真实条件句标记的用法,而且将来时标记和情态都是在假设的句法环境中完成转换的。表示确定义的副词是现实性的语法范畴,主要表示对客观存在的事实陈述,但是在假设的句法环境中仍然发展出了假设标记的用法。

英文摘要：

It is argued here that the term ＂irrealis＂ and ＂realls＂ are not the absolute binary. The future marker and modality are all belonged to irre]is grammatical category, thereby both are regarded as hypothesis markers in simple irrealis condition- als. However, not only irrealis grammatical category Can evolve the hypothesis markers, but some realis grammatical category can also evolve the hypothesis marker, such as some adverbs which express certa/nty. That means as a whole eontimuum, ir- realis and realis can transfer each other.