liczba odwrotna v angličtině:

a reciprocal relationship between citizens and the state

reciprocalagreement, obligation

she was hoping for some reciprocal comment or gesture

As long as Britain remains in the union, their pension and healthcare rights will be protected under defined reciprocal arrangements.

the treaty is a bilateral commitment with reciprocal rights and duties

There must be a reciprocal advantage; it should not always be one-sided.