used to do, be used to do 和be used to doing用法区别：
1.used to do sth. 过去常常做某事 (现已不做)
肯定句：主语+ used to do
否定句：主语+ didn't + use to do
一般疑问句：Did+主语+use to do
特殊疑问句：What + did+主语+use to do?
His father used to smoke.
→His father didn't use to smoke.
→Did his father use to smoke?
→What did his father use to do?
2.be used to doing sth. 习惯做某事
He is used to living alone.
They are used to listening to English songs.
He is used to eating meat.
I used to go shopping with Amy.
He used wood to make a fire.
The wood was used to make a fire.
The wood was used for making a fire.
以上就是used to do和be used to doing用法区别。