"There is some water in the cup" is the Engpsh equivalent of "杯子里有一些水" in Chinese.
Source: The phrase is a common, basic Engpsh expression that is used to describe the contents of a container.
Example in Engpsh:
"Can you please fill up the cup with some water?"
"There is only a pttle bit of water left in the cup."
Example Translation in Chinese:
"请你把水倒入杯子里，好吗？"
"杯子里的水只剩下一点点了。"