Later on, these marks were given grammatical functions.

之后，这些标点被赋予了语法的功能。

A simple and consistent set of endings indicates grammatical functions of words.

简单、一致的单词结尾决定了它的语法功能。

The suffix 'ed' has a grammatical function you probably know - it changes the tense of the verb to simple past tense.

后缀“ed”具有您可能知道的语法功能 - 它将动词的时态更改为简单过去时。

So the differences among these three terms is more related to their grammatical function in the sentence than it is their actual meaning.

因此，这三个术语之间的差异更多地与它们在句子中的语法功能有关，而不是它们的实际含义。