Keep an eye on someone/something 密切关注某人或者某事

Keep an eye on someone/something 字面上是用眼睛看着某人或者某事，实际上就是指密切关注某人或者某事的意思，还是非常容易理解的。
例如：
Always keep an eye on the baby when he is playing.
当这个婴儿玩的时候注意看着。
Watch someone/something carefully to make sure everything is all right
仔细看着某人或者某事确保没有问题。

有关这个短语的例句：

1. Basking on the balcony,granny can still keep an eye on the children.
   一边在阳台上晒太阳，奶奶还可以一边看孩子。
2. How did you make such great success on the East European market.
   你们怎么在东欧市场取得这么大的成功呢？ We always keep an eye on the East European market.
   我们一直很关注东欧的市场。
3. Can you keep an eye on my suitcase for a moment please?
   可以帮我看一下手提箱吗？

本文部分参考了ESLMonkeys.com