Ethan has learned how to shake his head no. We've never shook our head at him so I don't know where he got this from, but he started to do it on his own and then later equated it to the words 'no no'.
If we say 'no no' to him, he will shake his head in response and then smile and proceed to do whatever we told him not to do (usually crawling to an area that is not childproofed and unsafe or trying to ingest something that is not food). He is cute though so he gets away with it. At this stage he is still easily distracted so we can just show him another toy or read him a story and it usually does the trick.
What does Ethan say 'yes yes' and 'no no' to? Let's find out!