lost in translation

I  with lamentable awkwardness, but Austerlitz with such natural perfection that for a long time I thought he had been brought up in France. When we  switched to English, in which I was better versed, I was strangely touched to notice in him an insecurity which had been entirely concealed from me before, expressing itself in a slight speech impediment and occasional fits of stammering, during which he clutched d the worn spectacle case he always held in his left hand so tightly that you could see the white of his knuckles beneath the skin.