UPDATE:

He smiled at me and kept looking at me...

I wrote a sentence in highlighter and Nathan traced it. The para told him to write his name and he wrote an N. Then she said each of the next letters and he wrote each one! All capital letters. All pressing hard with a pencil.

..."Go glue this on your paper.” He went to his desk, got out a glue stick, glued it on, and put away his glue!!!!!!

...came back for more food for him because he quickly ate everything you had packed. 

In PE, Nathan RAN his laps—first time. When shown to do the side step, he imitated the teacher and did it. When instructed to walk backwards—he did it!