It 作为一个代词，常常做宾语，但有时用于某些动词或介词之后，构成一个习惯用语，这时的it意义不确定，或没有实际的意义。因此，被称为模糊宾语或假宾语。常有以下几种形式：
1.由实义名词转化为动词+it, 这时此名词具有了动词的功能，具体用法如下所示。
1)由表示交通工具的名词转化为动词+it 。常见的有：
to bus it(坐公共汽车去)，to taxi it(坐出租车去)，to subway it(坐地铁去)，to train it(坐火车去)，to boat it(坐船去)等，例如：
Shall we train it or boat it? 我们坐火车去还是坐船去?
The flight has been called off because of the storm, and we have to train it. 由于航班取消，我们只好坐火车去。
2)由表示人或动物身体部分的名词转化动词+it。常见的有：to foot it(步行, to leg it(逃走)，to hoof it(逃走)等, 例如：
We didn’t catch the last subway and had to foot it home. 我们没赶上最后一班地铁，只好走回家。
Because they can’t stand up to the close examination, the two prisoners failed to leg it before being caught again. 没能躲过严密地搜查，这两个囚犯没逃多远就被抓了回来。
3)由表示人，动物或事物的名词转化为动词+it, 常见的有：to lord it(称王称霸)，to queen it(做女王统治)，to pig it(象猪一样)，to hotel it, to pub it(住宿)等，例如：
Gone are the days when the cruel king could lord it over the whole empire. 这个残酷的国王统治的日子一去复返了。
We couldn’t get to the city before it was dark; we had better hotel it pub it. 天黑以前我们进不了城，我们最好住宿。
2.由不同词性的词语转化为动词+it，可以分为以下几种情况：
1)由形容词转化为动词+it ，表示这种形容词的动词功能，例如：
Are you going to brave it out? 你硬着头皮干下去吗?
The argument broke out, with some people shouting, “Cool it! Cool it! 争论发生了，一些人在一旁喊着：“冷静点，冷静点!”
2)由表示运动意义的动词+it, 常见的有：to walk it(走), to trip it(长途旅行), to go it(干)，to come it strong(做得过分，过于夸大), to go it blind(瞎干), to go it alone(单干), to go it strong on something(热烈地赞许某物)等，例如：
It is very near and we can walk it quite easily. 路途很近，我们很容易就可以走到的。
She is determined to go it alone. 她下决心自己去干。
3)由某些常用动词+it, 构成习惯用语，常见的有：to have it(了解), to catch it(挨骂,受责备)， to bear it(撒腿就跑), to rough it(过原始生活)，to make it(成功做成某事), to hop it(离开)，to take it easy(别紧张)等。例如：
You will catch it for breaking the glasses. 你会因为打破玻璃而挨骂的。
After failing in the exam for 3 times, he realized he would never make it in accounting. 3次考试失败后，他意识到他不可能取得会计资格了。
Bob studied hard deep into the night, and then decided to call it a day and went to a bed. 鲍伯学习到深夜，然后决定休息并上床睡觉去了。
Better stay inside today, Nancy, and take it easy. 南茜，今天最好呆在家里，别紧张。
He was hard put to it to earn a living for his family. 他艰难地挣钱养家。
4)由某些介词+it，构成习惯用语，其中of it 用于名词或最高级之后，表示加强语气。例如：
He had a hard time of it. 他过得很辛苦。
We must make a good job of it. 我们一定要把事情做好。
3.it还可以构成一些短语，用于某些插入语中做假宾语，常见的有：as luck would have it(碰巧)，like it or not(不管喜欢不喜欢)，believe it or not(信不信由你)，take it or leave it(要么接受，要么放弃),have what it takes(具备取得成功的必要条件)等。例如：
As luck would have it, no one was in the spot. 发生爆炸时，幸好没有人在现场。
The price of the car was 100 thousand yuan, take it or leave it. 汽车的价钱是10万元，要不要随你。
I don’t think Rebecca has what it takes to be a ballet dancer. 我认为Rebecca不具备成为芭蕾舞演员的条件。
It做模糊宾语的用法很多，在上述的每一个例子中都很难解释清楚它的具体含义，了解了其用法和特点，可以避免在阅读过程中陷入误区，搞不清逻辑关系而影响了阅读。反之，可以取得事半功倍的效果。
