What are two big events in Andrew Clements' No Talking?

The first big event in Andrew Clements' No Talking is the appreciation for silence Dave develops while studying Mahatma Ghandi for his report on India. Dave's new appreciation for silence leads him to think critically about his classmate Lynsey babbling about useless things and to say something insulting to her. Dave insulting Lynsey is a second big event, the event that guides the rest of the story.

While researching India, Dave learns that Mahatma Gandhi used "words and ideas" to practically drive the "whole British army out of India all by himself" (p. 11). Dave also learns that Gandhi spent one day out of every week in total silence as a way to "bring order to his mind" (p. 13). After reading this, Dave begins to think about his own talking habits and to wonder if silence might improve him, might make him smarter and better at playing sports. Therefore, Dave decides to challenge himself by taking Gandhi's vow of silence for the day, which is one of the first major events in the story.  

However, by the time he reaches lunch recess that day, Dave breaks his vow. During lunch, Dave overhears Lynsey babble to her friends for a very long time about how one of her classmates had bought the sweater she had had her eye on at a store and how the classmate had later tried to offer it to Lynsey as a gift, but Lynsey refused it. Hearing Lynsey babble on about her ridiculous behavior makes Dave lose his temper, and Dave shouts at her, "If you had to shut up for five minutes, I bet the whole top of your head would explode!" (p. 19). When Lyndsey retorts, saying that Dave talks about ridiculous things just as much as she does, Dave goes so far as to say something completely untrue: "[B]oys never talk as much as girls do, ever!" (p. 20). Dave's verbal attack on Lynsey is the second major event of the book and helps create the story's conflict. After this moment, all the kids in the fifth-grade class challenge each other to a vow of silence, boys vs. girls, and this silence causes unexpected problems at school.