In Harper Lee's To Kill a Mockingbird, what does Scout learn about the Ewells during the trial that she did not know before?

In Harper Lee's To Kill a Mockingbird, during the trial, much of what Scout narrates about the Ewells is information she has grown up learning about them. One thing she has learned about the Ewells while growing up in Maycomb is the fact that they live in a small cabin behind the town's garbage dump, near the Negros' cluster of cabins. Scout knows this because, every year per the mayor's request, Scout goes...

In Harper Lee's To Kill a Mockingbird, during the trial, much of what Scout narrates about the Ewells is information she has grown up learning about them. One thing she has learned about the Ewells while growing up in Maycomb is the fact that they live in a small cabin behind the town's garbage dump, near the Negros' cluster of cabins. Scout knows this because, every year per the mayor's request, Scout goes with her father and other Maycomb citizens to take their own Christmas tree and holiday rubbish to the town dump in respect of the garbage collectors. Therefore, Scout has had many opportunities to observe the Ewells' home and notes that it's not nearly as nicely kept as any of the Negros' cabins. She has also known throughout her childhood that the Ewells live off of the charity of the county.

However, one new thing Scout learns about Bob Ewell through the trial is that he is ambidextrous. His ability to write with this left hand is important to Atticus's defense to prove that Ewell had more ability to injure Mayella on the right side of her face than Tom Robinson. Another thing Scout learns about Ewell during the trial is that none of Maycomb's citizens have any respect for him, as seen in the "whispers and chuckles" that went on in the courtroom during his testimony (Ch. 17).

One thing Scout learns about Mayella Ewell during Mayella's testimony is that Mayella is unaccustomed to being shown respect, as seen in the fact that she thinks Atticus is mocking her when he calls her "ma'am" and "Miss Mayella" (Ch. 18). From Mayella's testimony, Scout further learns just how bleak life is in the Ewell home. They live in poverty; their father is an alcoholic who disappears for days; they have no sanitation; the young children are constantly sick; and, the children are kept out of school because the father feels he needs them at home to help with chores. Scout further learns that the father can be abusive when drunk.

Everything Scout learns about the Ewells helps paint Bob Ewell as the guilty party rather than Tom Robinson.