What are the earliest parts of speech?

最早的词类是什么词？

Preposition is one of the most active parts of speech in English.

介词作为英语中最为活跃的词汇之一，一直是传统教学的难点。

And there are no equivalent parts of speech between different languages.

有没有不同语言之间的语音相当部分。

I'd almost want to call them parts of speech in an animator's vocabulary.

我几乎要说这些是动画师词汇的一部分。

Different languages have different standards to distinguish parts of speech.

不同的语言有不同的标准来区分词类。