Amida Errors: Chonein HaDaat/Yismach Moshe/Tikanta Shabbat/Ata Echad/Rashei Chodashim/Ata Vichartanu

What: Chonein HaDaat/Yismach Moshe/Tikanta Shabbat/Ata Echad/Rashei Chodashim/Ata Vichartanu
Where: Amida 4th paragraph
Error #1: You Said the Wrong Paragraph on Shabbat or Jewish Festival
Examples
  • You said the weekday version on Shabbat or Jewish festival--or the reverse.
  • You began to say the version for a different Shabbat service (say, it is Shabbat mincha and you said the version for Shabbat shacharit).
WHAT TO DO
1) If you erroneously began the fourth paragraph for weekday on Shabbat or Jewish festival ma'ariv, shacharit, or mincha:
Finish the erroneous blessing and then begin the correct version. 
2) If you erroneously began the fourth paragraph for weekday at musaf:
Stop wherever you are and say correct fourth paragraph.  
3) If you began to say the fourth paragraph from the wrong Shabbat service:
It is OK, b'di'avad.
 
Error #2  You Said the Wrong Paragraph on a Weekday or at any Musaf:
 
Example
You said the weekday fourth paragraph at musaf for Rosh Chodesh.
WHAT TO DO
Stop wherever you are and say correct fourth paragraph.