what is to be done then 与what is doing then哪种说法正确还有：learn to do 与learn doing 两种表达都对吗,有什么区别?a child can't learn ______ (spell) without being helped.这里该填哪种?

what is to be done then 与what is doing then哪种说法正确还有：learn to do 与learn doing 两种表达都对吗,有什么区别?a child can't learn ______ (spell) without being helped.这里该填哪种?
what is to be done then 与what is doing then哪种说法正确
还有：learn to do 与learn doing 两种表达都对吗,有什么区别?
a child can't learn ______ (spell) without being helped.这里该填哪种?

what is to be done then 与what is doing then哪种说法正确还有：learn to do 与learn doing 两种表达都对吗,有什么区别?a child can't learn ______ (spell) without being helped.这里该填哪种?
第一个对.因为what is to be done 是被动式,事情是被做的,被处理的.what is doing没有主语.
前者是学习做某事.后者是learn by ...ing
I learn to speak English.
I learn English by working hard.
a child can't learn spelling without being helped.
这里的spelling是名词.