Interesting quote from the Yated (parshas Noach), in the middle of the article about Rav Yisroel Kanarek ZT”L from Peekskill (page 38):
He also accustomed himself to speak to the Bochurim in English because he felt that in that way he could have a much greater influence on them. He once said, “The reason many of the roshei yeshivah who came to America from before World War II were not as successful at transmitting the unique system of the European yeshivos to America, was because of the language barrier between them and the bochurim. The fact that they did not know English created a situation in which the they could not properly communicate with each other. Rav Aharon kotler was th only person who, by sheer power of his fiery personality, was able to penetrate and force his will on the American community despite the fact that he did not speak English.”