Reported imperfective is used for states, events or actions occurring habitually or repetitively, or happening during
the period of reference,
and expresses that the knowledge of the fact is the result of the speaker having been told of it,
very often indirectly, by hearsay. That knowledge is in general deemed as dubious.
Other possibilities are that the knowledge is the result of direct narration (but then also seen as dubious), or even of dreams.
The temporal distinction between a past and a present state, event or action is not marked grammatically,
the tense must be decided from the context.
The knowledge is very often the result of indirect hearsay:
Sen bilmas emishsan.
Some say that you don't know.
The knowledge is even more dubious when its topic is the speaker himself, otherwise, it implies a future value.
Biz Tojikistonda ishlar emishmiz.
Apparently, we would work in Tajikstan.
The state, event or action may have occurred in the past:
Yer esa, ko'ziga koptokdek bo'lib ko'rinar emish.
As for the Earth, it was appearing to his eyes as a ball.
Or quite often, it would occur in the future:
Ertaga mehmonlar kelar emishlar.
Apparently, the guests will come tomorrow.
Biz Xorazmga borarmishmiz.
They say we would go to Kharezm.