【used to do sth】和【be used to do sth】
①used to do 过去常常（表示现在不再）
eg:I used to swim in the lake near my village when I was young.
②be used to do 被用于.=④be used for sth./doing sth.
eg:Wood can be used to make paper.
③be used to doing习惯于做某事
eg:My grandpa is used to going for a walk after dinner.
③和①②很容易区别,而②可以认为和be used for doing sth意思一样.
【be used to do 和be uesd for sth /doing sth.都可以表示“被用来……（表目的）”区别如上,动词的形式不同.
e.g.The knife is used to cut apples.
=The knife is used for cutting apples.】