You must have heard Bohr talk.
Once or twice, yes, in English, and of course that always handicaps.
Bohr couldn’t even speak Danish well. He actually had an impediment in his speech which hampered him no matter what language he used. But in addition to that he had such an intense desire to be precise in his utterance that he made it very difficult both for himself and his audience. It would have been far better if when he gave a speech, he had read it from a manuscript. He refused to do so almost always, and this was much, you might say, to his credit; but in view of all his difficulties it was a mistake, because it meant people very rarely understood what he was saying.