Question :
Those who bless a berachah and in the middle of the blessing they hear Kaddish or kedushah or other blessings, may he answer amen on Kaddish or other blessings, or to answer to kedushah?
Answer:
In the blessings of the commandments (hamitzvot), or the blessing on the beneficiary (nehenim), and the blessings of praise (shevach) it is forbidden to answer amen on Kaddish, kedushah, or barchu. But with long blessings he may answer Kaddish, kedushah, or barchu. But not to answer amen on blessings such as that found in the blessing of asher yatzar or the blessing of the moon, etc. Although answering amen of the blessing itself that stands in it is not considered a ‘hefsek’ at all. Although regarding the blessing of ‘meain shalosh’ such as eating fruit from seven species as an annulment or drinking wine, even if one heard Kaddish, kedushah, barchu, or amen of blessings is not allowed to stop.
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