【I couldn't understand why you did it like that】

问题补充：

I couldn understand why you did it like that way?这里面 I 是主语,情态动词的否定加上 动词understand ,那 why you did it like that way 算什么成分?还有一个问题就是 find 和believe是 系动词还是 别的什么动词？

答案：

i 主语 understand 谓语 why you did it like that way 宾语从句 find believe 是实义动词

======以下答案可供参考======

供参考答案1:

why you did it like that way 作宾语，整个句子作宾语叫做宾语从句。

供参考答案2:

宾语从句。我无法理解为什么他会那么干。

供参考答案3:

作为谓语understand的宾语从句。