Question

why did the three not exchange a single word while driving back from Poleta

Answer 1

Heya !

Nicolo and Jacopo's mind were overflowing with the thought of their progress for their next payment and the narrator knew that the two boys didn't like him to discuss about their infirmed sister so in order to keep it as a secret and make them feel proud of what they did for their sister he didn't ask anything about Lucia. ..

hope this helps you

Answer 2

The three didn't exchange a word while driving back from poleta as the author didn't want to invade their privacy or make them feel that their secret family history has been leaked to someone so he made them feel that their secret is safe with them. The author had a great sense of respect for the 2 brother's selfless nature. This is the reason why the three of them hadn't exchange a single word with each other while driving back from poleta.