cost的用法、意思、过去式、过去分词详解
cost 英[kɒst] 美[kɔ:st]
cost这个单词的基本意思是“花费;价钱;成本;费用”的意思，它可以作名词也可以做动词。
第三人称单数：costs 复数：costs 现在分词：costing 过去式：cost 过去分词：cost
首先我们以它的词性来看看它的用法。
1、cost作名词
cost可以是可数名词，意为“费用;花费;价钱”，指购买、做某事或制造某物的总价值是多少钱。如：
The cost of a loaf of bread has increased five-fold. 一条面包的价钱增长了4倍。
In 1989 the price of coffee fell so low that in many countries it did not even cover the cost of production. 1989年咖啡的价格跌得那么低，以致在许多国家还抵不上其生产成本。
Badges are also available at a cost of £2.50. 徽章也有卖的,2.5英镑一枚。
cost作为复数名词使用，意为“成本，费用”。如：
The company admits its costs are still too high. 该公司承认其成本仍然过高。
Costs have been cut by 30 to 50 per cent. 成本降低了30%到50%。
He was jailed for 18 months and ordered to pay £550 costs. 他被监禁了18个月,还责令他支付550英镑的诉讼费。
cost可以做为不可数名词使用，意为“成本，成本价”。如：
...a store that provided cigarettes and candy bars at cost. 按成本价出售香烟和糖果的商店
...a practice known as dumping – that is, selling below cost to drive competition out of business. 倾销行为——即通过以低于成本的价格销售产品来挤垮竞争对手
cost做为定语名词，通常用来修饰另一个名词。如：
cost consciousness; cost overruns. 成本意识；成本增量
2、cost作动词
cost作及物动词，意为“费用；花费”的意思。
This course is limited to 12 people and costs £50. 该课程只招收12人,学费为50英镑。
Painted walls look much more interesting and doesn't cost much. 彩绘墙壁看上去更有趣而且花费也不高。
It's going to cost me over $100,000 to buy new trucks. 要买新卡车得花掉我10万多美元。
cost作不及物动词，指需要特定的费用、支出、努力或丢失：
It costs more to live in the city. 在城市居住要付出更多东西
3、cost的搭配
① cost sb. sth. 花费某人（多少钱）；让某人付出（代价）／牺牲……
The work costs me two weeks.这个工作花了我两周时间。
② at all costs/at any cost 不惜任何代价。无论如何
Attend it at all costs, even if you are late. 无论如何你也要参加，即使你迟到了。
We must be on time at all costs. 我们无论如何要准时到达。
He ordered the army to recapture the camp at any cost. 他命令军队无论如何也要夺回营地。
③ at cost （price） 按成本价格，按原价
I can spare you some, if you want, at cost. 你如果想要，我可按成本让给你一些。
This is the lowest prices. We are selling at cost already. 这是最低价了。我们是按成本销售。
④ at the cost of 以……为代价，用……换来的；丧失；牺牲
He bought fame at the cost of health and happiness. 他牺牲了健康和幸福换来了名誉。
⑤扩展其它搭配
It costs sb some time/money/energy to do sth.
sth costs sb some time/money/energy.
cost of capital 资本成本
Cost of Equity 权益成本