Q. For the purposes of kiruv, I want to initiate unaffiliated Yiddin into reciting brochos, by saying them in English, is it permitted?

A. It is definitely better to recite brochos in the original Lashon Hakodesh (Mishna Berura 62: 3, 167: 53, 185:1) as one is to adhere to the primary decrees of our sages and the Holy Tongue contains many concealed connotations and spiritual nuances not present in other idioms. Besides, when brochos are recited in other languages one must understand the true translation and meaning of the brocho and must be in a venue where others do so also (Biur Halocho 62: 1, Aruch Hashulchan and Shulchan Aruch HoRav ibid.) However, in case of need, when one lacks the know how, he may recite brochos in other established languages (Shulchan Aruch O.H. 62:1, 185:1, 206: 3, Igrois Moshe O.H. 2: 49)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a