1、用作动词时，为及物动词，表示“冒……的危险”“使遭受危险”。如：
They risk their lives in order that we may live more safely. 他们冒了生死危险使我们生活得更安全。
后接动词作宾语时，要用动名词，不能用不定式。如：
They risked losing everything. 他们冒失去一切的危险。
A lot of people run the risk of being killed. 许多人冒着被杀害的危险。
2、用作名词时，注意以下用法：
(1)要表示冒危险，通常与动词run, take等搭配。如：
Why run the risk? 为什么要冒这种危险?
There was so much to lose (that) we couldn’t take any risks. 损失这么多，我们不能冒任何风险了。
(2)表示“……的危险”，其后通常不接不定式，而接of doing sth。如：
He dare not run [take] the risk of being caught by the police. 他不敢冒被警察抓住的危险。
There’s not much risk of losing money if you bet on that horse. 如果你押那匹马，输钱的风险不太大。
比较run [take] the risk of doing sth与run [take] a risk in doing sth：前者指冒做某事的危险或风险，其中的of doing sth为修饰the risk的定语；后者指做某事有危险或冒风险，其中的in doing sth是状语，in有类似when的含义。如：
I took a risk in telling him the news at that moment. 我那时把消息告诉他，那是冒了风险的。
(3)注意以下习语的用法：
①at risk 处境危险，在危险中
How much at risk is the smoker? 吸烟者的危险性有多大?
②at one’s own risk 对发生的事负责，自担风险
Persons swimming beyond this point do so at their own risk. 游泳者超越此界限若有意外后果自负。
③at the risk of 冒……的危险
He saved my life at the risk of losing his own.他冒着生命危险救了我的性命。