Hmmmm...

Everett can say 'truck'.
Unfortunately, the way it comes out does not sound like 'truck' but rather another word that sounds a lot like 'truck' but begins with a different letter.
And...
He calls all vehicles he sees (trucks, trains, cars, etc.) his version of 'truck' so he's running around saying it all the time...
Guess we won't be going out in public for a while.