crazy unschooling

Aharon, age 4, just came over to me and asked me how to write "shoes."  I said s-h-o-e and he interrupted me and told me he wants to write it down.  I figured he was going to type it.  But no, he got a marker and apparently went to write it down on a piece of paper.

"Okay, go!" he said, marker ready.

"S," I said.

"Yeah?" He is writing.

"H," I said.  "Chana, he doesn't know how to write, does he?"

Chana shrugs.  Neither of us have seen him write.  I'm pretty sure he knows his letters (I'm not sure how, probably from TV shows or the computer.  They don't really like "educational" games but they all learned their letters without me teaching them).

"He knows his letters," Chana said.

But I didn't think he could write letters.  Just because he recognizes letters doesn't mean he can write them, does it?