Friendship, at the age of two

Kittyboy has a friend his age now! The little boy from two doors down, I'll call him Bobby, is almost exactly six months younger, and they've taken an interest in each other. Two-year-olds don't really have friends so much as... life-size living toys. It's quite funny that they don't seem to know what to do with each other - except chase and run and laugh at each other's antics!
It's very interesting to watch them and see the differences in development, Kittyboy at almost two and a half, and Bobby at almost two. Bobby is taller by an inch or so, and ten pounds heavier. Kittyboy learned to kick deliberately just last month, while Bobby's been kicking fairly competently this whole spring. But where Kittyboy will run up to something like a railroad tie and step up and over it with no assistance whatsoever, Bobby can't do that yet. He puts a foot on the railroad tie and reaches for someone to steady himself. If Kittyboy had been full-term, he'd only be three months older, and therapists put him at about Bobby's age anyhow when they rate his abilities, so it's fascinating to see what each one can and can't do. It's a pretty even comparison.
Communication is complicated by the fact that Kittyboy follows primarily English, and Bobby's first language is Spanish. So while they're waving their arms and babbling urgent-sounding proclamations at each other, they have NO idea what the other is trying to say, because they're not "speaking" the same language! Naturally, this means their communication is through gestures and demonstrating what they want, which works quite well.
We had a sad day yesterday, because Kittyboy took his Pooh ball outside. Ooooh, bad idea. It's a rubber ball with Pooh on one side and Tigger on the other, bright and colorful. And coveted, by any toddler who likes balls and Pooh. Kittyboy was actually eager to share, to my surprise, but then Bobby didn't want to give it back... So his mama and I were trying to explain this whole sharing concept, and the idea of possession (that someone else may own the thing you want, and so it can't be yours), and it didn't go well. Kittyboy in tears and holding his treasured ball very tightly, poor little Bobby inconsolable, mommies carrying sad little boys towards their respective front doors.
I did find out, while we were working on sharing, that Bobby LOVES BALLS, and loves Pooh, and does not, in fact, have a ball with Pooh on it. So I went to Menards, where I originally found the ball in question, and got another - exactly like it. Names on each with Sharpie. We are prepared. They're the only toddlers on our little road, and perhaps in the whole neighborhood - they HAVE to be able to play together, and if the ball is going to be a problem, that's an easy fix!