2. Tell Them You Don’t Understand
Try telling your child that you don’t understand their whining voice and that if they talk in their normal voice that you’ll be able to understand them. Keep telling them this until they stop whining and start asking in a normal voice. You could even demonstrate to your child the difference in your voice by asking them to do something by whining and then asking them the same question in your normal voice. Ask them which one was easier to understand and more pleasant to listen to. Explain that when they whine to you you can’t listen to them and that you will not be able to understand them until they speak normally.