It's time to ...和 it's time for ...区别?急.It's time to ...和 it's time for ...在任何情况下都可以相互转换吗?例如：1.It's time to brush teeth.2.It's time for teeth.3.It's time for brushing teeth.哪位可以回答啊1.2.3.到底

It's time to ...和 it's time for ...区别?急.
It's time to ...和 it's time for ...在任何情况下都可以相互转换吗?
例如：1.It's time to brush teeth.
2.It's time for teeth.
3.It's time for brushing teeth.
哪位可以回答啊1.2.3.到底哪句是正确的?
这个两个句型任何情况都可以转换吗?有什么条件吗?
望高手指教,最好举例说明,

这三句都正确.
to后跟的是动词原形：It's time to have lunch.
for后跟的是名词或动词的ing形式：it's time for lunch
it's time for having lunch
这样应该可以了吧