Throughout the second half of the novel, Janie, who once spoke her mind about whatever she wished, grows quieter. This is not apparant all the time, for she still speaks constantly. However, it is as if she has chosen to sensor herself. She has mastered her impulse to speak her mind, no matter what the consequences. You might think that this is a sign of weakness, but I find it as a sign of strength. It takes a great deal of self control to remain silent at the times when you most want to speak your mind. Janie, unsatisfied with the way that she is dominated by the men in her life, found a way to convey her power through her silence.
This is shown in chapter 17, when Janie is being beaten by a jealous Tea Cake. Tea Cake beats Janie as if to show her that she belongs to him. If this had happened earlier in the novel, Janie probably would have been very angry and spoke out against Tea Cake. However, Janie takes the beating silently and does not hold a grudge against Tea Cake. In this way, Janie is showing her power over Tea Cake. She is silently conveying that it does not affect her to be beaten down, that she is strong enough to bear the pain. This way of asserting her power, is much more powerful than a sulky complaint would have been. Janie took the beating like a man, proving to Tea Cake that she is stronger than ever. In this way, Janie has become more powerful. She does not use meaningless words to try to prove her power. Rather, she uses silence as if to show how strong she really is.