当“费用，成本”讲的时候，是可数名词，加s，作“代价，损失”讲，是不可数名词，不加s。expense可数不可数皆可,做“开支,经费”解释时常用复数形式。不可名词 spending of money etc;可数名词cause of spending。

expense

读音：英 [ɪkˈspens] 美 [ɪkˈspɛns]

释义：n.费用;花费的钱;消耗;花钱的东西

vt.向…收取费用;把…作为开支勾销

第三人称单数： expenses

复数： expenses

现在分词： expensing

过去式： expensed

过去分词： expensed

例句：

1、It was said that he went to great expense to install a lift in the building.

据说他花费巨资在大楼里安装了一台电梯。

2、It was not a fortune but would help to cover household expenses.

这笔钱不算多，但是能帮助支付家庭开支。