can not help 的用法

can't help doing sth
禁不住做某事
如：
When he heard the news, he couldn't help crying.

但要注意区别有的试题会这样考，这时便是帮不了忙的意思
can't help to do sth 换句话说就是和help to do的否定句
如：Mum, I'm so busy .So I can't help to clean the room today.

can not help:
禁不住,忍不住

Examples:
1. Have a lot of doubt, he can not help asking them question.
因为他有些疑问，他禁不住向他们提问。
2. She can not help smiling.
她禁不住微笑起来。
3. But one hundred and ninety is their final bid. I can not help it.
但190美元是他们的最终出价，我也没有办法。
4. I can not help think the same.
我不禁也有同样的想法。

cannot help doing something

She cannot help eating up the whole bucket of ice-cream.