Deliberate.

For a long time, I've been saying that A is playing with this or doing that, and M tells me that it's not on purpose.

Today, he is definitely doing things on purpose. I held him in his crib and he was at eye level with the monkey on his mobile. He reached out and batted at it. He turned away, and I said "Do it again," and swung the monkey. He batted at it again and then grabbed on to its leg.