Function words are words that have a grammatical purpose.

虚词具有语法功能。

The reason Americans reduce helping verbs is because they are function words.

美国人略读助动词的原因是助动词是虚词。

Our content words fall on the beat. Function words are off beat.

我们的实义词都在节奏上面，而功能词则在节奏以下。

And prepositions are function words, which means they’ll generally be unstressed i n a sentence.

介系词是虚词，就是它们通常说在一句句子里被轻读的。

That is because these words are function words.

这是因为这些词都是虚词。

Function words have a grammatical purpose but do not carry much specific meaning.

虚词有语法目的，但没有多少具体的意思。

It's what we call a function word; it's not important.

这就是我们所说的虚词，它并不重要。

It's just there for grammar purposes and this is what we call a function word.

它只是出于语法目的而存在，这就是我们所说的虚词。

This would mean it's become a function word.

这意味着它变成了一个功能词。

Although function words are usually not stressed, Gregory stresses it because he is noting its importance.

虽然功能词通常不重读，但格雷戈里重读它是因为他注意到了它的重要性。