Tom has only been educated by his aunt and Sunday school, and other than that he's rather untaught. Even with the lack of teaching he is still a rather smart boy not in wits but in cleverness. He is crafty from all his time spent working and getting things for his auntie. Most terms he uses will require a dictionary to understand while others are just horribly misspelled.
Besides the lack of schooling that Tom gets he's a rather smart boy and one I'd watch out for