若宾语是动词不定式、动名词或从句，可用it作形式宾语代替其位置，而将其放到宾语补足语后面。例如：

I found it's difficult to finish the task in time. 我觉得按时完成任务很困难。

Do you consider it any good sending more people there? 你觉得再多派一些人去那会有好处吗？

We have made it clear that we disagreed. 我们已清楚的表明我们不同意。

主语补足语：含宾语补足语的句子改成被动语态时，原宾语和宾语补足语便分别成为主语和主语补足语。例如：

We found him working in the office. 我们发现他正在办公室工作。

He was found working in the office. 他被发现在办公室工作。