My pops, having immigrated from the old country, and remaining in an immigrant neighborhood where English needn't be spoken, never acquired the English language skills to communicate effectively in that language. But he was as sharp as a tack, shrewd as a fox, patient as a Saint, knew how to bide his time, and above all - knew human nature well.
Consequently, he was underestimated all his life. And quite honestly, often to his advantage such as during business negotiations, he knew how to trap opponents in a corner, before they even knew it. Think: "Columbo". I'm not sure if some of these guys even realized they'd been beaten, but instead thought that they screwed up and the "stupid guy" ....