All kids whine at one age or another, but the way to turn this attention seeking behavior into a habit is to give in, and let your nagger win. Once you give in, you can count on your kids to continue using this technique to get what they want. If not stopped, whining often escalates into back talk, arguing, and tantrums.
You can stop your child's whining habit with a little patience and time. The best way to stop the behavior is to not listen to nagging requests unless spoken with a normal talking voice. If your child whines, "I want a drink," then say, "I can help you when you ask in a normal voice." You may need to role model the correct way a normal voice verse a whining voice. Let your child know that you will not tolerate and respond to whining. Usually whining stops when kids realize it's getting them nowhere. If your child is still whining you can set up a consequence every time they whine. Wherever the whining occurs is where the consequence must take place. If you are out, you can have them sit quietly with no interaction with you. Consequences help stop behaviors only if they are used every time and with consistency when the behavior occurs. If you tell your child they are getting a consequence, follow through or the behavior will increase, only because your child has learned you might give in.
Please remember to praise your child when they use their words and in a normal voice without whining. Breaking the habit takes time. Don't get discouraged. Whining is a learned behavior and can be unlearned with consistency, love, and patience.