there is surely some doubt about that 还有一个句子 i am sure in favor of your decision这两个句子为什么一个用surely 一个用sure

there is surely some doubt about that 还有一个句子 i am sure in favor of your decision这两个句子为什么一个用surely 一个用sure
there is surely some doubt about that 还有一个句子 i am sure in favor of your decision
这两个句子为什么一个用surely 一个用sure

there is surely some doubt about that 还有一个句子 i am sure in favor of your decision这两个句子为什么一个用surely 一个用sure
有一个简单的办法
There is surely some doubt about that如果去掉surelyThere is some doubt about that也说得通,说明surely应是副词,起修辞作用另外,I am sure in favor of your decision 这句话有语法错误sure用在这里是错误的,应该用副词I am definitely in favor of your decision.或者I am sure (that) I am in favor of your decision.

因为doubt为动词，意为怀疑，用副词修饰，而in favor of为介词短语，而且为 i am 加形容词加上介词短语