Question: Two mourners are reciting Kaddish at different speeds. How should you answer Amen to their Kaddish?
Short Answer: Although others disagree, the Mishnah B’rurah rules that if the two mourners are within “toch k’dei dibur” – three or four words from each other – then you may answer Amen to whichever mourner you want, and this will count for both of them. However, if they are more than three or four words apart, then you should answer Amen separately to both of them.