What is Bob Ewell's testimony in To Kill a Mockingbird?

Bob Ewell testified that he saw Tom Robinson with his daughter Mayella.

Bob Ewell’s testimony is colorful and fanciful.  He tries to convince the jury that Tom Robinson raped Mayella.  However, he admits that no one went to get a doctor for her.  Atticus tries to establish that Mayella was never attacked at all by having Ewell demonstrate that he is left handed.

“Well, Mayella was raisin‘ this holy racket so I dropped m’load and run as fast as I could but I run into th’ fence, but when I got distangled I run up to th‘ window and I seen—” Mr. Ewell’s face grew scarlet. He stood up and pointed his finger at Tom Robinson. “—I seen that black nigger yonder ruttin’ on my Mayella!” (Ch. 17) 

Mr. Gilmer tries to show that Mr. Ewell saw Tom Robinson attack Mayella.  However, when Atticus questions him on cross-examination, he asks Bob Ewell if he went for a doctor.  Ewell says he never thought to. 

“Didn’t you think she should have had a doctor, immediately?”

The witness said he never thought of it, he had never called a doctor to any of his’n in his life, and if he had it would have cost him five dollars. “That all?” he asked. (Ch. 17) 

Atticus also has Mr. Ewell describe her injuries and point out that they were on the left side of her face.  He has Mr. Ewell write his name so that the jury can see that he is left-handed.  He is trying to show that Mayella’s injuries were caused by her father. Later, he will demonstrate that Tom Robinson has no use of his left arm.

Atticus hopes that people will understand that Bob Ewell was lying when he said that he saw the rape, because Mayella did have injuries, but not caused by Tom Robinson.  No one got her a doctor.  If she really had been raped, wouldn't a doctor have been called?

When Bob Ewell gets on the witness stand, to what does he testify in To Kill a Mockingbird?

Simply put, Bob claims that Tom Robinson has raped and beaten his daughter, Mayella. According to Bob's testimony, he returned to his house, looked in the window, and

"--I seen that black nigger yonder ruttin' on my Mayella!"

Much to his pleasure, Bob's statement sends the courtroom spectators into an uproar. Bob claims that Tom not only raped Mayella but also beats and chokes her, causing the bruises on her neck and face. Bob also "holds with Tate"--he agrees with all of Sheriff Tate's testimony, that no doctor was called and that the right side of Mayella's face was bruised. Atticus also requests that Bob write his name, and he did so with his left hand.

Scout and Jem (and most readers) choose to believe Tom's testimony: that Mayella hugged and kissed him while he was trying to get a box off the top of her chiffarobe, and Bob appeared as Tom was trying to run away. Since Atticus proved that Mayella's bruises could only have been inflicted by a left-handed man (Bob writes with his left hand); and since Tom's left arm is crippled, it can be assumed that the only other person present--Bob Ewell--choked and beat his own daughter. Bob must have been angry to see Mayella kissing a black man and, according to Tom, Bob told her,

"... you goddam whore, I'll kill ya."

What does Bob Ewell say that undermines the prosecution in To Kill a Mockingbird?

In Harper Lee's To Kill a Mockingbird, the moment in which prosecution's case against Tom Robinson is hurt the most is when Bob Ewell agrees with Sheriff Heck Tate's testimony about Mayella Ewell's injuries. While Ewell is on the witness stand, Atticus has the court reporter reread Sheriff Tate's testimony that Mayella was bruised in her right eye. The problem with this testimony is she would have had to have been hit by a left-handed man facing her. It is later shown that Robinson has been crippled in both his left arm and left hand since his childhood.

While Ewell is on the witness stand, Atticus destroys Ewell's credibility as a witness when Atticus asks him if he can read and write. When the answer is yes, Atticus asks Ewell to sign his name on an envelope Atticus extracts from his pocket. When Ewell does so, Judge Taylor notes, "You're left-handed, Mr. Ewell" (Ch. 17). Mr. Ewell immediately recognizes what Atticus has just managed to demonstrate. Scout notes in her narration that "Mr. Ewell turned angrily to the judge and said he didn't see what his being left-handed had to do with it, that he was a Christ-fearing man and Atticus Finch was taking advantage of him" (Ch. 17). Since it is physically impossible for Robinson to have injured Mayella's right eye and very possible for Ewell to have done so, we can see that Atticus has destroyed the prosecution's case by pointing to Ewell as the more guilty culprit through circumstantial evidence.

What do we learn from Bob Ewell's testimony in To Kill a Mockingbird?

Bob Ewell is the father of Mayella Ewell, the girl Tom Robinson is accused of raping. He feels that Atticus is taking advantage of him. Mr. Ewell's story remained the same throughout his testimony and cross-examination. The reader learns a few things due to Atticus' clever cross-examination.  The reader learns that Mr. Ewell isn't very educated and seems very arrogant while on the stand. The key thing the reader learns is that Mr. Bob Ewell is left-handed. This small bit of testimony shows that the injuries described by Sheriff Heck Tate was caused by someone left handed.