impossible

Compared meaning: not able to be done or achieved (adjective).

比较义项：不可能实现／不可行的（形容词）。

• impossible 本词

  Broader and stronger: describes anything that cannot happen or be achieved at all, not limited to plans; used for tasks, requests, or situations in general.

  含义更宽泛也更强烈：指任何完全无法发生或达成的事情，不局限于计划，也可用于任务、要求或各种处境。

  It seemed impossible to finish all the work in one day.

  看起来要在一天之内做完所有工作是不可能的。

• unworkable

  Narrower: specifically describes a plan, system, or method that fails to function successfully in practice, even if it is not literally impossible.

  含义更窄：专指计划、制度或方法在实际操作中无法成功运作，即便从理论上讲并非绝对做不到。

  Their original plan turned out to be completely unworkable in practice.

  他们最初的计划在实际操作中被证明完全行不通。

Impossible and unworkable both mean something cannot be done, but differ in scope. Impossible is stronger and broader, used for any task, request or situation that cannot happen at all. Unworkable is narrower and milder: a plan or system that fails to work in practice.

两词都可以形容“做不成”的事，但程度和对象不同：impossible 语气更强、更绝对，指完全不可能发生或达成的事，适用范围很广；unworkable 语气较委婉，专指计划、方案或制度在实际操作中无法成功运作，并不一定说它绝对做不到。