Regarding the saying of “Nacheim” at Minchah on Tish’a B’Av:
- One says “Nacheim” even if one is not fasting
- If one concludes the berachah with the “regular” chasimah, one does NOT have to repeat anything.
- If one forgot to say it in its proper place, one should say it where one normally says “ya’aleh v’yavo”. And in that case, the chasimah should be the “regular” chasimah of “hamachazir….”
Most Acharonim hold that if one is bentching, one says “Nacheim” in the bentching where one usually says “ya’aleh v’yavo.” The “regular” chasimah should be said.