《初中语文六册·常见文言虚词》释“怅恨久之”的“之”:“句末的结构助词,没有实在意义。”这一提法值得商榷。我认为结构助词应该是显示词与词结构关系的词。而“怅恨久之”中的“之”,不具备这一特征,因此不能认为它是结构助词。那么,“怅恨久之”中的“之”应该是什么词呢?让我们对该句试作以下比较探索: “Literature in junior high school, six volumes, common idioms and words” explains “the hatred for a long time”: “The structural auxiliaries at the end of the sentence have no real meaning.” This formulation is debatable. I think the structural particle should be a word that shows the relationship between the word and the word structure. However, the “Zi” in “hate for a long time” does not have this feature and therefore cannot be considered a structural particle. So, what should be the word “zhi” in “hate for a long time”? Let’s make a comparative study of this sentence: