stop 常见三种用法：

1. stop doing sth：停止正在做的事
2. stop to do sth：停下来去做另外的事
3. stop sb from doing sth：阻止某人做某事= prevent sb from doing sth

After 1 hour, they stopped playing football.
一个小时之后，他们停止了踢球。

After walking for an hour, he stopped to have a rest.
步行了一个小时之后，他停下来休息。

We must stop him from throwing the rubbish everywhere
我们必须阻止他到处乱扔垃圾。