We use ordinal numbers to see which comes first.

当看是哪个先的时候，使用序。

And fiftieth is the correct way to write the ordinal number.

而 fiftith 才是序词的正确写法。

Finally, you might also hear ordinal numbers used as an adjective.

最后，你可能还会听到序用作形容词。

Ordinal numbers are numbers that show the order of things.

序词表示的是事物的顺序。

Ordinal numbers are one important area of grammar that connects with the Olympics.

序是与奥运会相关的一个重要语法领域。

It's very rare to see an unabbreviated ordinal number in a written date.

非常常用这种写法当写整个日期的时候。

All of the other ordinal numbers end in a TH.

所有其他以TH结尾的序词。

When you're ordering things, so when ordinal numbers like second, fifth, are used as adjectives.

当你给某些事物排序时，那么这时序词像是第二，第五，作为冠词使用。

But in the Olympic games, ordinal numbers are of central importance.

但是奥运会上，序才是最重要的。

Ordinal numbers can act as nouns, adjectives, or adverbs.

序可以充当名词、形容词或副词。

The three most important ordinal numbers in the Olympics are first, second, and third.

奥运会上最重要的三个序号是第一、第二和第三。

Ordinal numbers also can act as adverbs.

序也可以充当副词。

Ordinal numbers suggest an order of things – think the order of winners in the Olympics.

序代表事物的顺序--想想奥运会获胜者的顺序。

" Second" is what we would call an " ordinal (ordinal) number."

“第二” 就是所说的“序（ordinal）” 。

You'll see a number up here, it'll be an ordinal number.

大家会看到字出现这里，它会是一个序词。

" Ordinal numbers" put things in order.

“序” 使事情井然有序。

In both cases, the ordinal number is acting like a noun.

这两个例子中，序的作用都像一个名词。

One type of transition signal is ordinal numbers. Listen.

一种类型的转换信号是序。 听。

The ordinal numbers are first, second, third, fourth and so on.

序为第一、第二、第三、第四等。

It's still directly before that ordinal number.

它仍然直接该序号之前。