当在 other 之前使用不定冠词 an 时，就变成了单个词 another，意为“又一，再一”，“不同的，类似的，可选的”。
一、another 作代词，例如：
This knife is blunt, can I have another?
这把刀钝了，能再给我一把吗？
I don't like this room. I'm going to ask for another.
我不喜欢这个房间。我打算另要一间。
This wall needs another coat of paint.
这面墙需要再刷一层漆。
二、another 作限定词，一般情况下后面接单数名词，例如：
We afford another trip abroad this year.
今年我们负担不起再出国旅行了。
We can fit another person in my car.
我的车里还可以坐进一个人。
Danny's had yet another car accident.
丹尼又出车祸了。
但是如果 another 跟“时间、钱、距离，数量”等时，名词也可以用复数形式，例如：
I need another two minutes to finish the test.
我还需要两分钟来完成测试。
It will be another three months before we can go back to the earth.
我们要再过三个月才能返回地球。
My passport is valid for another two years.
我的护照有效期为两年。
I another 10 dollars.
我还需要10美元。
He could have been trusted to drive another ten miles in search of some appliance.
他可以被信任驾车再走十英里去寻找某种器械。
三、one another 相当于 each other，是一个代词，例如：
We all try and help one another.
我们都尽力互相帮助。
I think we've learned about one another in this session.
我认为这段时间我们相互有了很多了解。
四、one way or another 译为“不管怎样，无论如何”，例如：
We'll get out of this mess one way or another.
不管怎样，我们都会摆脱困境的。
I didn't really care one way or another.
管它怎样，我真的不在乎。
五、one (…) after another 译为“一个接着另一个”，例如：
I'm not surprised he's feeling ill, because he was eating one ice cream after another!
他病了，我一点也不奇怪，因为他一个接一个地吃冰淇淋！
解析：because 用来说明对听众来说很重要的事情的原因。
They had faced one difficulty after another with bravery and dedication.
他们以无畏和无私奉献的精神迎接了一个又一个的困难。
The guests came one after another.
客人们陆续来了。