If someone makes a brocho but says “ADINOY” for Hashem’s Name instead of “ADOI-NOY”, can we answer “Amain”? Does he have to repeat the brocho correctly?
If somebody pronounces the Name of Hashem as mentioned in the question, he would have to recite the blessing again. Mention of the Name is an integral part of the blessing, and if the name is pronounced in a manner that is clearly wrong, the blessing is not valid.
However, such a blessing would still fall under the category of thanking Hashem for the food, and would probably not be worse than saying brich Rachmanah mara de’hai pita. Accordingly, there is room to discuss whether or not it would be wrong to say amen after the blessing. The leaning lema’aseh is that amen should not be said.
See Berachos 40b; Beis Yosef 167; Magen Avraham 187. Concerning amen, poskim write that one should not answer amen after a berachah that involves a prohibition (see Orach Chaim 215:4; Biur Halachah 92:1; Shulchan Aruch Harav 215:4; Aruch Hashulchan 215:5), and this is extended by Peri Megadim (Eishel Avraham 25:10) to a blessing that might involve a prohibition. Due to this concern for an “amen in vain,” it would appear correct to refrain from answering amen, even though the blessing in our case does not involve an actual berachah levatalah, because the Name of Hashem was never actually recited.
Amen should therefore not be recited, because one does not recite amen over an improper blessing.
See Berachos 40b; Beis Yosef 167; Magen Avraham 187.