(Last week we discussed if one began to say the weekday shemoneh esrei by mistake on Shabbos…)
BUT, if the person only said the word “ata” of the first weekday beracha, then:
- If this happened at ma’ariv or mincha, the person may continue with the proper Shabbos shemoneh esrei (since their Shabbos beracha also starts with ata).
- If it happened at shacharis, and it was a slip of the tongue, the person should immediately stop, and start the Shabbos shemoneh esrei.
- If, at shacharis, it happened because the person thought it was a weekday, the person should continue and conclude the beracha of ata chonein, and then continue yismach Moshe.
- If it happened at mussaf, the person should stop immediately, and start saying tikanta Shabbos.
ALL these rules apply also if the person said “ata cho” or “ata chon”