(1)pay作动词时,意思是“付款”或“支付”,多以人为主语,可以有被动语态.
短语pay for
是付款,为...花费的,主语是人
如：I'm afraid (that)if you've e lost it ,you must pay for it .
I haven't paid the seller yet .
The doctor was paid 500 dollars for the operation .
(2)cost作动词用时,意思是“值……钱；价值为,花费”.以物或事做主语,不能以人作主语,也不能用于被动语态.
句型sth cost sb some money
物花费的钱
如：I like this dress ,but it costs too much .
This pencil—box cost me ten yuan .
不能说I cost ten yuan for this pencil—box .
也不能说I was cost ten yuan for this pencil—box .
但却可以说I paid ten yuan for this pencil—box .
或者还可以说I spent ten yuan on this pencil—box .
(3)spend只能作动词用,意思是花费(钱、时间),渡(时光、假期),多以人为主语.
句型sb spend some money on sth.
sb spend some time doing sth.
人花费钱或时间
She spent a lot of money on clothes .
(= she spent a lot of money in buying clothes .)
I went back to my home town to spend my holidays last summer .
Half his money was spent for medicine
(4) take v.花（某人）（钱、时间）去做……,多以it 作形式主语.
句型it takes sb some time to do sth
it开头的,只用于花费时间
例：It took him a lot of money to buy a fur coat .
他买皮衣花了很多钱.
注意：It takes sb .some time to do sth .(某人做某事花费时间)
该句型只能表达“花费时间”而不能用于“花费金钱”.
如：It takes him two hours to do his homework every day .
(He spends two hours)
不能说It took him five yuan to buy these apples .
而应该说He spent five yuan on these apples .
或者说He paid five yuan for these apples .
还可说These apples cost (him) five yuan .