使 つか らしたそうだ
tsukainara shita sōda

Godan Verb (su)
Evidential Auxiliary

Expresses hearsay about a past event ("I heard that...") of 使い慣らす

1. It seems they're used to it.; It's said they're familiar with it.; They say they've gotten used to it.

Past/Perfective
Hearsay Evidence