《英语难题研究一千例》的作者许孟雄教授曾在书中解答 I'll foot it 的意思等同于I'll go on foot. 我也看到过 We foot it all the night. 这样一句, 是否可以理解为“我们走了一整夜”？it  在句中做什么成分？

解答如下：

We foot it all the night.

参考译文：我们跳了一整夜的舞。

foot it 一般用于口语种主要有以下2个意思

(1)走着去

We have missed the last bus, so we'll have to foot it.  我们没有赶上最后一班公共汽车, 只有步行了.

We didn't catch the last subway and to foot it home.  我们没赶上最后一班地铁,只好走回家.

As there is no bus and cab, I had to foot it.  没了公共汽车和出租车, 我不得不步行.

We decided to foot it over to the convenience store.  我们决定步行去便利店.

We missed the last bus and to foot it.  我们误了最后一班车,只好步行.

Finding no carriage, I had to foot it.  找不到车子, 我只好步行.

(2)跳舞

We foot it all the night.
参考译文：我们跳了一整夜的舞。