Your once-mellow baby has become an opinionated 2-year-old who responds to your request to put away her toys with a hands-on-her-hips, head-cocked “You’re not the boss of me!”

Brat Buster: Count to three. A snappy comeback might help you blow off some steam, but there is no dignity in mudslinging with a minor. Instead, remember that this is a teachable moment: Say something like, “I know what you really meant to say is, ‘Sure, Mommy, I’ll pick up my toys.’” Then help by giving clear, specific instructions that she can follow. Remember, she’s only 2 — you need to help her focus on what you want her to do.

The Big Picture: Think of your toddler as a scientist. She’s trying to discover with her sassy stance what kind of reaction she can provoke. She may have realized already that if she picks up her toys when you ask, you’ll go check your e-mail or start dinner. But a little back talk and — wham! — the kid now has your full attention. So don’t slip away and attend to business when your child is happily engaged. Instead, focus on her. This positive reinforcement will gradually teach her that she doesn’t need to provoke you to get your attention. When she does give you attitude, don’t take the bait, but don’t ignore it either. “Call her on it in a clear, simple, unemotional way,” says Dr. Borba. Come up with a statement and automatically use it every time you feel she’s crossing the line. For example: “That’s rude talk. Please rewind and try it again.”

Your 4-year-old comes home from a long day at school in a crabby mood, sprawls out on the couch, and whines for ice cream. When you say “No dessert until after dinner,” he looks you dead in the eye and yells: “You’re stupid, Mommy! I hate you!”

Brat Buster: Your child’s back talk may be more an expression of the frustration he feels as a small child in a big world rather than intentional rudeness. “We talk about the ‘terrible twos,’ but 4-year-olds are challenging too. They want to be independent but often feel incredibly helpless,” says Sara Grunstein, a clinical social worker in Berkeley, California. It’s best if you don’t respond angrily when he calls you a name like “stupid”; instead, remind him that name-calling is mean — and hurts people’s feelings. Then ask him to rephrase what he wants to say in a nice way.

The Big Picture: Behaving all day at school is hard work. So it’s no surprise that many kids wait until they get home to let it all hang out. Understanding that moodiness is a coping strategy can help you keep your cool. First, make sure your child has had a healthy snack and isn’t exhausted. Conversely, he may have a lot of pent-up energy from sitting still all day that he needs to use up. If so, go on a bike ride or blast some music and dance around the living room. Later, when you’re cuddling on the couch, remind him that there’s a rule against using mean words in your house. “A great way to communicate the nuances of polite versus rude talk to 4-year-olds is by reading and telling stories about other children’s sassy behavior,” says Grunstein. “Your kid will absorb the lesson without even realizing it.”

You tell your 5-year-old to turn off the TV, and she throws the remote on the floor, runs into her room, and slams the door.

Brat Buster: Being angry is okay, but your child has to learn that hurling objects and slamming doors is always against the rules. At age 5, kids still have a hard time dealing with anger, but they’re old enough to learn from consequences. “Your child needs clear, consistent punishment when she behaves like this,” says Hilary Flower, author of Adventures in Gentle Discipline. “If she knows you’re in control, the bad behavior will disappear fast.” In this case, calmly take away a privilege, like watching a favorite TV show for a week, and explain why you’re doing it. Don’t back down no matter how much your child pleads or apologizes.

The Big Picture: Learning how to feel mad without behaving badly is something even grown-ups struggle with. “Kids who react physically when they’re feeling angry are usually doing it because they don’t have another way of expressing this overwhelming emotion,” says Henry A. Paul, MD, author of When Kids Are Mad, Not Bad. So the long-term project is to give your kid constructive ways to communicate her feelings. Help her get used to describing her emotions with words or a drawing rather than with a temper tantrum.

Dinner’s almost ready and you call out from the kitchen, “Are you ready to start setting the table?” As usual, your kid barely looks up from his Game Boy. After you ask him several times, he says mockingly, “I don’t know. Am I?”

Brat Buster: Kids this age actually love a chance to give a little back talk. It fits perfectly with a school-age child’s sense of humor, desire to test you, and quest to stake out some independent territory. “Your mistake was asking your child a question instead of giving a direct instruction,” says Karin L. Price, PhD, a clinical psychologist at Texas Children’s Hospital’s Learning Support Center for Child Psychology. “If you make it a request, then you’re inviting him to decline.”

Big Picture: Friends are a huge influence on a 6-year-old. Your child almost can’t help himself from bringing home the snarky comebacks that spread like a virus around the playground. Even if you’re super strict about the TV, movies, and video games your kid is exposed to, the best-loved popular culture of the grade-school set is filled with potty humor and name-calling — an all-out celebration of brattiness itself. Now’s the time to start laying down rules about appropriate ways to talk in front of adults versus around their friends. Since fitting in is so important, you don’t want to take the joy out of playground chatter, but be clear and firm about your expectation: Rude retorts are banned when grown-ups are around. Finally, don’t forget to praise him when he’s polite. “It’s much easier for your kid to know how you want him to act when he gets positive feedback for his good behavior,” says Dr. Price.