118. Aneinu

19:13 If the shaliach tzibbur made a mistake in his personal Shemoneh Esrei, he does not go back and repeat it because this would inconvenience the entire congregation. Instead, he may rely on the communal prayer that he will say out loud. Since this doubles as his personal Shemoneh Esrei, he would say the paragraph “Elokai, n’tzur l’shoni” and step back at the end. If the shaliach tzibbur made a mistake in the first three blessings and remembered in a point where starting over would not inconvenience the congregation too much, he should repeat Shemoneh Esrei. (Mishnah Brurah 126:17 cites the Tur, who does not require the shaliach tzibbur to repeat Shemoneh Esrei even in this case.) 19:14 On a fast day – even a private fast – one adds “aneinu” at mincha, in the blessing of “shema koleinu.” If a person forgot to add “aneinu” and he has already said God’s Name in the conclusion of the blessing, he does not go back to say it. Instead, after finishing Shemoneh Esrei and the paragraph of “Elokai, n’tzur l’shoni” but before moving his feet to step back, he says aneinu until the phrase “b’chol eis tzara v’tzukah” and then he concludes with the verse “yihiyu l’ratzon.” If he has already taken his three steps back, he would then not say aneinu at all.