A few days ago, I was preparing DS2.5 to go to the park with DH when DS began to deliberate out loud how to negotiate sharing his toys with other children. (NB: A few days prior, DH had reiterated to DS the importance of being gentle with other children, as DS is quite a strong and physical child. He has taken to referring to his age-mates as "weak babies"...his cringe-worthy choice of words.)
This is what DS had to say:
Mummy, if a weak baby wants to share my shovel and says ( DS raises his voice to a falsetto ), "DS, may I please use your shovel?" I will say, "Yes, weak baby, you may. I would be delighted to share my shovel with you. Would you like to play with me?"
But if the weak baby doesn't ask nicely, I will say, "No, weak baby, you may not use my shovel. I'm busy using it." If the weak baby tries to snatch it from me, I will say, "Excuse me, weak baby. You're crowding me. Please step back."
If the weak baby still keeps grabbing my shovel, I will get Daddy and he will say ( DS lowers his voice to impersonate DH), "Weak baby, please give that shovel back to DS." And he will look at the weak baby's parent to get them to make the weak baby give it back to me.
Me: It sounds like you have your plan all figured out. So you'll only play with polite children?
DS: Yes.
Me: I think that's a good policy.