单独, 独自

• for oneself与by oneself
  for oneself与by oneself
  ■for oneself 有两个用法：
  1. 自己，亲自
  You can judge for yourself. 你可以自己做出判断。
  He demanded the right to decide for himself. 他要求得到自己做决定的权力。
  2. 为自己，替自己
  He made no complaint for himself. 他没为自己诉苦。
  She’s wangled an extra week’s holiday for herself. 她多弄到一星期的假。
  He acted without thought for himself. 他那样做的时候并没考虑到自己。
  ■by oneself 有三个用法：
  1. 单独地，独自地（= alone）。如：
  I like to travel by myself. 我喜欢独自旅行。
  She was sitting by herself on a bench. 她独自坐在一条长凳上。
  I ofte

by oneself/for oneself/to oneself
You must do your work by yourself.你必须独立做你的工作。
Do you have anything to say for yourself?你还有什么要为自己说的吗？
What are you talking to yourself about?你自言自语说些什么？
<辨析>by oneself 意为“独自的”，“无助的”，强调某人独自做某事，而不需别人帮助，还可说 all by oneself 以加强语气。如：
This box is too heavy for me to lift by myself.这个箱子太重，我一个人提不起。
We have got to do it all by ourselves.我们必须自己来干。
for oneself 解作“为自己（的利益而做某事）”，还可作“独自地”解，与 by oneself 同义。如：
He has built a house for himself.他为自己建造了一幢房子。
You must find it out for yourself.你必须自己把它找出来。
to oneself 意为“暗自”，“在心中”，常与 talk,say,think 等动词连用。如：
He said to himself that there was something wrong.他想这其中有毛病。
注意：say to oneself 意为“在心里想”，talk/speak to oneself 意为“自言自语”，两者不可混淆。