Lister P. Katt doesn't speak English

So Lister has this funny knack for shaking his head at either totally appropriate times or really inappropriate times.  It seems to go in phases for awhile his head only shakes to things that should be yes then for awhile he only does it for no.

So just now I asked him tons of questions.  No kitty shaking of the head just blank kitty stare.  Finally,  I go to leave the room but first I ask "Lister don't you speak English?".  He quickly shook his head. 

Ohh and the Katt spelling is on purpose, I asked Brian how he spells Lister's full name, as I was pretty sure he didn't spell it Cat... I was right, it's spelled Katt after Bucky Katt.  Oddly enough Lister kind of looks like Bucky but I'd have to say Dutchie acts more like him while Lister acts like the dog Satchel :P