Ⅰ. hear “听见”指听力，强调听的结果。如：
① I often hear Lucy sing in the next room.
Ⅱ. hear of “听说”强调间接听到有关某人的情况或得到消息。有时可用about 代替of，意义无多大的区别。如：
① We are all glad to hear of your success. 听到你成功的消息，我们都很高兴。
② Have you heard of her lately? 你最近听到她什么情况吗?
Ⅲ. hear from “接到……的来信(电话等)”如：
① Hope to hear from you soon. 希望你早点来信。
② We have not heard from him since he left. 自从他离开后，我们一直没有收到他的来信。