⑴.基本用法
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”。这类动词如：Find ,think ,feel, imagine, believe, consider如：
● I find it difficult to do the job well. 我发现做好这件事不容易。
⑵. 用作形式宾语的几个特殊结构
①.动词+ it + that-从句。如：
● You can put it that it was arranged before. 你可以说这是以前安排的。
● Rumor has it that the defence minister will soon resign. 据传闻，国防部长不久就要辞职。
【说明】能用于此结构的动词不多，常见的有 have, take, put, like 等。
②.动词 + it + when (if)-从句。如：
● I dislike it when you whistle. 我不爱听你吹口哨。
● We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。
● I’d prefer it if I didn’t have to do so much work. 要是我不必做那么多工作，好就太好了。
【说明】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。
③.动词 + prep + it + that-从句。如：
● See to it that you’re not late again. 注意千万不要再迟到。
【说明】能用于此结构的动词不多，常见的有see to, look to, insist on, stick to, depend on, answer for 等。
④.动词 + it + 介词短语+ that-从句。如：
● I owe it to you that I am still alive. 多亏有你我才仍然活着。
● I took it for granted that he would help us. 我认为他会帮助我们的。
【说明】能用于此结构的动词不多，常见的有take it for granted, bring it to sb’s attention, owe it to sb 等。