1 used when the people or things who do an action are also affected by it （表示人或动物受自己行为影响）他们自己，她们自己，它们自己: Helen and Sarah seem to be enjoying themselves. 海伦和萨拉似乎玩得很快乐。People often talk to themselves when they are worried. 感到忧虑的人往往自言自语。

2 used to emphasize ‘they’ （用于强调they）: They themselves say that the situation cannot continue. 他们自己说不能让这种情况继续下去。Did they paint the house themselves? (= or did sb else do it for them?) 这房子是他们自己油漆的吗？

1 alone 独自: The boys are too young to go out by themselves. 那些男孩太小，不能让他们自己出去。 ☞Look at the note at alone. 参看alone的注释。

2 without help 自行；独力: The children cooked the dinner all by themselves. 孩子们自己烧了晚饭。