She was adamant that she would not come.

I am sure that the project will be finished.

以上两句可以有三种分析结果：

一、划线部分为前面形容词的“补足语”：

She was adamant that she would not come.

I am sure that the project will be finished.

二、划线部分整体作“表语”：

She was adamant that she would not come.

I am sure that the project will be finished.

三、划线部分的 that 从句，作系表结构的“意义宾语”（系动词 + 形容词，理解为“及物词组”）：

She was adamant that she would not come.

I am sure that the project will be finished.

建议网友，不要拘泥于一种分析，更不要把精力用在结构分析上面。