through 可以作介词，作副词，也可以作形容词。

一、through 作介词

1、用来暗指从某物的一个位置到另外一个位置，通常是某物的两端，意为“从…一端至另一端；穿过，贯穿”，例如：

You have to go through the forest to get to the village.

你必须穿过森林才能到达村庄。

解析：此句说话人使用through来说明你必须从森林的一端穿到森林的另一端。

2、用来给出方式或原因，意为“以，凭借；因为，由于”，例如：

You can only achieve success through hard work.

你得孜孜不倦方能成功。

It is through your own fault that you lost this opportunity.

你失去这个机会是由于你自己的过错。

The accident happened through no fault of mine.

事故不是我的错。

3、用来表示通过障碍、阶段或测试，意为“穿过，通过”，例如：

It was through great difficulty that we finally achieved this.

我们是经过极大的困难才最终达到这一目的的。

First you will have to go through an exam.

首先你得通过考试。

此意可以延申为某事已经完成，意为“完成”，例如：

Finally, we are through with all the exams.

最后，我们完成了所有的考试。

4、用来指示从一个活动，一种情况或是一段时间的开始到结束，意为”自始至终；从头到尾“，例如：

The children are too young to sit through a concert.

这些孩子太小，音乐会没完就坐不住了。

He will not live through the night.

他活不过今天夜里了。

二、through 作副词

1、意为”从一端到另一端；通过“，例如：

Conductors let electricity through, but insulators don't let through.

导体让电流通过，而绝缘体则不让通过。

The flood was too deep to drive through.

洪水太深，汽车开不过去。

2、意为”自始至终；从头至尾“，例如：

Don't tell me how it ends─I haven't read it all the way through yet.

先别告诉我书的结尾，我还没有看完呢。

I expect I'll struggle through until payday.

我想我会挨到发薪日的。

3、意为”接通“，例如：

He may find the line cut on the telephone so that he can't get through.

他可能会发现电话线被切断了，所以打不通。

I rang him several times this morning but could not get through to him.

上午我给他打了几次电话，但都没打通。

4、意为”直达，径直“，例如：

This train goes straight through to York.

这列火车直达约克。

You can check your baggage right through to its final destination.

你可以把行李直接托运到终点。

5、意为”通过…“，通常是障碍、阶段或测试等，例如：

The lights were red but he drove straight through.

红灯亮着，但他开车闯了过去。

6、用于形容词后，意为”完全，彻底“，例如：

We got wet through.

我们浑身上下都湿透了。

I returned to the inn cold and wet, soaked through by the drizzling rain.

我回到小旅馆时身上被毛毛雨淋透了，感觉又冷又湿。

三、through 作形容词

1、用来表示线路或路线直通的，意为“直达的，直通的”，例如：

The village lies on a busy through road.

那村庄坐落在一条繁忙的直达公路上。

This is my first journey by the through train to Guangzhou.

这是我第一次乘直达车去广州。

2、（使用）完成，结束；（关系）了结，断绝

Are you through with that newspaper?

你看完那份报纸了吗？

I'm through with the explaining.

我不想再解释了。

It would be only a matter of time before he went through with it.

他完成这件事只是时间问题。

Todd and I are through.

托德和我吹了。