used to 后加动词原形:过去常常干某事 只有能用于过去式中
be/get/become used to 后加动词ing (即doing) 习惯于做某事,时态不限 但是be/get/become要随时态的改变而改变
be used to 后加动词原形:其实是一个被动语态 “被用于干...”
be used for 后加名词性短语或者是doing “被用于.事”
例1 He used to swim in winter.他(过去)常常在冬季游泳.
例2 I am used to reading every morning.我现在习惯早读.
例3 Cell phone is used to communicate.手机(被)用于交流
例4 CUP is uesd for prograssing information.CPU被用于处理信息.