The silver lining: Your toddler isn't purposely trying to irritate you. Whining begins around age 2, when kids can talk a little but are still used to crying to get what they want, says Carolyn Crowder, Ph.D., coauthor of Whining: 3 Steps to Stopping It Before the Tears and Tantrums Start. To help your child learn a better way to ask for what she wants:
Teach her to be aware of her tone. When she whines, tell her once that the problem isn't what she's saying but how she's saying it. (Don't mimic your child -- if she hears you whining, she'll think it's acceptable for her to do it, too.)
Stop responding to it. Make it clear that if she whines for something, you'll automatically say no. Or pretend you can't hear her if she does it.
Stand firm. Even if you do this, your child will still whine. It'll take a Herculean effort to ignore it, but give in a few times and she'll see that whining works. (Toddlers learn from your actions much more than your words.) When your child alters her tone and speaks normally, give her your full attention.