His spare money goes on books.

他多余的钱都花在买书上。

I have no spare money this month.

这个月我没有馀钱。

All his spare money went on books.

他所有的余钱都花在书本上了。

We don't have spare money.

我们没有余钱。

All his spare money goes on books.

他的零花钱都买书了。