Question

谁知道这句英语的语法结构啊？

在书上看到这样一句话：
He didn't know what he was going to but it had to be better than what he was leaving behind.
我是知道它的翻译，但是不太理解这句话的语法结构，哪位仁兄能帮我分析一下吗？
例如:what he was going to是宾语从句。但but后面的句子，它的语法似乎看不太懂啊！
求解答啊，可以说得具体些吗？谢谢啦！

Answer 1

it是形式主语，真正的主语是后面的what从句，后面这句话的谓语是had to be

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但是如果按照你说的，那么就会是：
What he was leaving behind had to be better than.
那个better than之后怎么没有了宾语呢？

Answer 2

it应该指 what he was going to

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那之后的what he was leaving behind，是什么从句呢

追答

what he was going to应该跟what he was leaving behind作比较，分别是主语从句。

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为什么是主语从句呢？我看着像宾语从句啊？

追答

but分句可改写为what he was going to had to be better than what he was leaving behind。what he was going to(do）相当于A，what he was leaving behind相当于B，句子可理解为A had to be better than B。