can't help but to do有to吗?can't but do为什么就没有to?

can't help but to do有to吗?can't but do为什么就没有to?
can't help but to do有to吗?can't but do为什么就没有to?

can't help but to do有to吗?can't but do为什么就没有to?
can't help but to do是固定的短语,表示只能怎样
而can是情态动词后面要加动词原形do

can't help to do是固定的短语，而can是情态动词后面要加动词原形do

can't help but do 不得不做
can't help to do 在做（什么）事方面帮不上忙
就是BUT和TO的区别， 前面是帮不上忙但只能做什么才行，就是不得不（只能）做
后面就是帮不上忙去做什么
个人理解， 仅供参考啦……