动词不定式可以用作宾语,为使句子平衡,常用it 作形式宾语,而把真正的宾语不定式后置。这同不定式作主语用it代替的情况相同。
I find it easy to do the work . 我发现做这项工作很容易。(to do the work为真正宾语 )
He found it difficult to get there on time. 他发现按时到达那里很难。
I think it useful to learn a foreign language. 我认为学习一门外语是有用的。
She thought it interesting to go fishing . 她觉得钓鱼是很有趣的 。
It is interesting to go fishing . 钓鱼是很有趣的 。(to go fishing作主语 )