I hear him talk with someone为什么talk不用加s.

I hear him talk with someone为什么talk不用加s.
I hear him talk with someone为什么talk不用加s.

I hear him talk with someone为什么talk不用加s.
hear sb. do 表示听到某人做某事.hear才是本句子的谓语动词.talk是非谓语动词.不用三单