instead 与 rather

副词 instead 与 rather¹ 可用来表达相似的意思，但两者通常不可互换。以下，我将简要解释 instead 的原始意思以及 rather 与其相似的意思，并以例句说明其一般用法。

instead：取代、代替；作为替代品。

1. The doctor told the patient to move his left hand, but he moved his right hand instead.
2. Instead of oscillating, this function diverges monotonically.
3. To reduce cost, we used brass instead of platinum.

rather：更适当地、更正确地、更准确地；作为更好或更适当的替代方案。

4. This result does not contradict the previous results. Rather, it demonstrates that there are situations to which the existing theories simply do not apply.
5. Rather than give up now, we should redouble our efforts.
6. This is not an established result. Rather, it is a tentative conclusion that is apparently inconsistent with at least one experimental result.

¹ Rather 还有其它意义，与此处讨论的完全不同。