What's the difference between 終わった and 終わっていた


> ① いつの間にかパーティーは終わっていた  
>  ② いつの間にかパーティーは終わった

How do you interpret the two sentences above?




This ～ている expresses "the continuation of state" as described in detail in
[When is Vている the continuation of action and when is it the continuation of
state?](https://japanese.stackexchange.com/q/3122/5010)

  * パーティーは終わっていた。 = The party had ended.
  * パーティーは終わった。 = The party ended.

The former form is used when, for example, you visited somewhere but found
there was already no one left. The latter is used when you just heard a
closing address from the host.

