Tamal Krishna Goswami: Prabhupada first gave Gayatri mantra in Boston, and then in September of 1968 he came to San Francisco and gave some of us Gayatri mantra. He taught us how to chant and gave out a sheet with the Gayatri mantras. Jayananda found it difficult to pronounce the mantras, so he decided to ask Srila Prabhupada about the pronunciation and he took me along with him. We sat in front of Srila Prabhupada and Prabhupada asked him to pronounce the mantras. As Jayananda tried, Prabhupada leaned back and roared with laughter. Prabhupada shook his head and said, “It’s hopeless. But it doesn’t matter. Because you are so sincere, Krishna will accept your chanting.”
Source: Remembrances by Sidhanta Das – Folio Vedabase