You use him to refer to a man, boy, or male animal.
John's aunt died suddenly and left him a surprisingly large sum.
约翰的姑妈突然去世,给他留下一笔令人意想不到的巨款。
Is Sam there? Let me talk to him.
萨姆在吗?让我和他谈谈。
In written English, him is sometimes used to refer to a person without saying whether that person is a man or a woman. Some people dislike this use and prefer to use 'him or her' or 'them'.
If the child encounters 'hear', we should show him that this is the base word in 'hearing' and 'hears'.
如果孩子遇到 hear这个单词,我们应该向他说明这个词是 hearing和hears的词根。