It may be the hardest thing for toddlers and preschoolers to do. No, we're not talking about potty-training. The dreaded s-word - sharing - can incite tantrums like no other. But the earlier you start teaching and modeling sharing, the better your child will become at sharing. Start helping your child understand the concept by buying just one of his favorite treat that's easily shareable - M&Ms, French fries, whatever it might be, dole out the item, allowing the child to take what he wants. Then next time, give the child the container and ask if he can share with you. Take notice not only when playing results in conflict, but also when it's going well. Praise kids for playing well together, saying something like, "It's nice to see you two having fun and playing so nicely."