I've just had an early morning coffee with my wife and two friends. One is a retired university professor of European literature and the other is a French retired fonctionnaire who grew up andstudied in London whilst both parents worked for the French diplomatic service. We switched between two languages comfortably. Then we heard something on the radio in the background and without taking in the content went into a discussion about spoken French.
The professor speaks several languages as his shelves packed with Shakespeare, Goethe, etc would hint. The other also learned a couple more, my wife and I are lingually skilled for other reasons although neither of us has ever studied a language beyond the school class. It was the professor who began to talk about why so many Anglais he knows have lived here 20 years and upward but still cannot understand or speak French. He is very slow and precise in his speech in each language, as am I too and generally my wife. The other man does do some very French things that were pointed out. He stumbles into "er, er, er" as often as one might expect but the more excited or animated he becomes then the more often he does it. Our learned friend said that the French use their language too excitedly and that a temperate, precise speech (as his own I suspect was meant) is clear and has no stutters. The other man thought about it, slowed down and sure enough no "er, er, er" and blurred and slurred together words until a contentious point arose and he sped up so that lo and behold... I need not say what recurred.
It is an interesting point. Is it the reason so many people do not learn? I have the radio on behind me now and can write this and follow them speaking, albeit it right now the "er, er, er" and excited blather bits jar on reflecting our discussion. However, I can see why people cannot understand. Now, being an inquisitive social scientist, I want to know what other people think of that?