He works hard to be a great writer.
问题描述：
He works hard to be a great writer.
to be a great writer划线提问.
What does he work hard for?
为什么不是What does he work hard to?
答
What does he work hard for?
把这个句子改成陈述句是 ：
he works hard for what .
for what 是为什么 for 表示目的,要是to what 就是对什么了,to 表示方向.