1. 他们自己;她们自己;它们自己
    You use themselves to refer to people, animals, or things when the object of a verb or preposition refers to the same people or things as the subject of the verb.

    e.g. They all seemed to be enjoying themselves...
           他们好像玩得都很开心。
    e.g. The men talked amongst themselves...
           那些男人一起聊着天。

2. 他们自己，她们自己，它们自己(强调所指的人或物，有时用作动词或介词宾语，代替 them)
    You use themselves to emphasize the people or things that you are referring to. Themselves is also sometimes used instead of 'them' as the object of a verb or preposition.

    e.g. Many mentally ill people are themselves unhappy about the idea of community care...
           许多精神病患者本身不喜欢社区护理。
    e.g. Cities themselves are changing rapidly...
           城市自身在日新月异地变化。

3. (用以代替himself or herself，指代句子的主语，而不指明是男是女;有人认为这种用法不对)
    You use themselves instead of 'himself or herself' to refer back to the person who is the subject of sentence without saying whether it is a man or a woman. Some people think this use is incorrect.

    e.g. What can a patient with emphysema do to help themselves?...
           肺气肿病人能做些什么来帮助自己恢复健康？
    e.g. Nobody was prepared to commit themselves.
           谁都不愿作出承诺。

4. (用以代替 himself or herself，强调所指代的人，但是不指明是男是女; themselves 有时也用作动词或介词的宾语;有人认为这种用法不对)
    You use themselves instead of 'himself or herself' to emphasize the person you are referring to without saying whether it is a man or a woman. Themselves is also sometimes used as the object of a verb or preposition. Some people think this use is incorrect.

    e.g. Each student makes only one item themselves...
           每个学生自己只做一项。
    e.g. After all, what more can anyone be than themselves?
           毕竟，人们除了做自己又能怎样呢？