be used for意为“（某物）被用做……”其后接名词、代词或动名词.如：（1）This kind of bamboo can be used for water pipes .这种竹子可用作水管.(2）A knife can be used for cutting bread .刀可用来切面包.be used to do sth.也可表示“（某物）被用做……”,但其后接动词原形.如：A hammer is used to drive nails .锤子是用来敲钉子的.提示：be used as相当于be used for的用法.如：The girl is being used as a servant in the house .这个女孩在家里被当做佣人使唤着.