Question

The rain (stop) before we (return) home​

Answer 1

The rain stopped before we returned home

Answer 2

The rain (stop) before we (return) home​

Answer:

Before we returned home, the rain had stopped.

We need to use certain words ''after'', ''until'', ''as soon as'', ''the moment that'' before using the past perfect simple.

we need to use ''before'',  ''when'', ''by the time'' before the past simple.

The past perfect tense is formed by using the auxiliary verb ''had'' together with the ''past participle''(Verb 3)

The correct sentence will be:

Before we returned home, the rain had stopped.

returned => past simple

had stopped => past perfect