We have a small white board on the outside of our door where we write the phone number of the apartment building we manage so prospective residents can get the number when we aren't home. E was playing outside and wanted to write and draw on the board, so I pulled it down to her level. She wrote what looked like capitol U's over and over again, and then said "Look, mom! L, M, N, O, P." I said, "Cool! Can I write L, M, N, O, P too?" She said yes, so I wrote the letters underneath hers. She looked really intently at them and said "Oh, that's not an L!" and erased the side of her U, so that it became an L.
For about half an hour, she wrote on the board, erased it, and wrote some more. Each time she finished, she showed me what she wrote. Sometimes she wanted me to tell her what it looked like she had written. Sometimes she wanted me to write letters and she tried to copy them. Other time she wanted to tell me what she wrote, and needed me to just say "Cool!"