其结构是固定的，意思上的主语并不是句子的主语。

• generally speaking
  一般说来
• talking of (speaking of)
  说道
• strictly speaking
  严格的说
• judging from
  从……判断
• all things considered
  从整体来看
• taking all things into consideration
  全面看来
• Judging from his face, he must be ill.
  从他的脸色看，他一定是病了。
• Generally speaking, dogs can run faster than pigs.
  总的来说，狗比猪跑得快。 (speaking 并不是dogs 的动作)