1.hear作为行为动词听见时，

hear sb do sth表示“听到某人做了某事”或“经常听到某人做某事”，

hear sb doing sth.表示“听到某人正在做某事”

2.hear about 听说,hear about + sth 听到关於某事物的消息
I've just heard about his promotion. 我刚刚听到了他被提升的事。

3.hear of + sb./sth 听到或知道某人[某事物]的情况
I have never heard of him since he left. 自从他离开后，我再没听到过他的消息。
I have heard of the song. 我曾听说过这首歌。（注意：这里提及的不是听到这首歌，而是听说过这首歌)

4.hear from + sb=receive a letter from 接到某人的来信、 电话等
Do you hear from you daughter this week? 今周你有收到你女儿的信吗？

5.hear 宾语从句: 听说或得知（某事物）
I heard (that) Tom would leave here. 我听说Tom会离开这里.
注意: 上句是宾语从句,当that在宾语从句中作连词引导从句时,that可省略。

hear vt. 听到，听；听说；审理
hear sb可以听见某人说话
可以说I can hear you

1.主动语态中，hear只能接不带to的不定式或动名词作宾语即：
hear sb do sth:       I heard her sing that song.    我听见过她唱那首歌。
hear sb doing sth  ：I heard her singing that song.  我听见她在唱那首歌。

2.但是，在被动语态中，又要将不定式前加上to,就以上面两句为例：
She was heard to sing that song.  她被人听到过唱那首歌。
She was heard singing that song。 她正在唱那首歌时被人听到了。