1 动词 “fall” 可以表示 “掉落，落下”。

In the autumn, the leaves start to fall.

The book fell off the shelf.

* 在美式英语中，名词 “fall” 可以用来指 “autumn（秋天，秋季）”。 

2 动词 “fall” 可以表示 “跌倒，摔倒”。

When learning to walk, toddlers fall a lot.

The floor was so slippery that they both fell over. 

3 与上面的动词相对应，名词 “fall” 可以表示 “倒下，摔跤”。

When learning to walk, toddlers fall a lot but they're usually not bad falls.

His back was badly injured from the fall.

4 动词 “fall” 可以表示 “（大小、数量或力量）减少、降低”。

No one knows why the house prices have fallen.

The temperature fell below zero last night.

5 与上面的动词相对应，名词 “fall” 可以表示 “（大小、数量或力量）减少、降低的事实”。

There has been a fall in house prices recently.

There's been a dramatic fall in the size of the rainforest.

6 动词 “fall” 还可以用来谈论 “变成（某种状态）”。

She fell asleep during the concert.

The crowd fell silent after his speech.